N3mo LC

Minimum Capacity Box

Wed, 13 May 2026 00:00:00 GMT

Given an array of box capacities and an item size, return the index of the box with the minimum capacity that can store the item, or -1 if none can.

Same Tree

Tue, 12 May 2026 00:00:00 GMT

Given the roots of two binary trees p and q, check if they are the same or not. Two binary trees are considered the same if they are structurally identical and the nodes have the same value.

Symmetric Tree

Tue, 12 May 2026 00:00:00 GMT

Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).

Maximum Depth of Binary Tree

Tue, 12 May 2026 00:00:00 GMT

Find the maximum depth of a binary tree by calculating the number of nodes along the longest path from the root node down to the farthest leaf node.

Balanced Binary Tree

Tue, 12 May 2026 00:00:00 GMT

Given a binary tree, determine if it is height-balanced. A height-balanced binary tree is defined as a binary tree in which the left and right subtrees of every node differ in height by no more than 1.

Pascal's Triangle

Tue, 12 May 2026 00:00:00 GMT

Generate the first numRows of Pascal's triangle where each number is the sum of the two numbers directly above it.

Single Number

Tue, 12 May 2026 00:00:00 GMT

Given a non-empty array of integers where every element appears twice except for one, find that single one.

Linked List Cycle

Tue, 12 May 2026 00:00:00 GMT

Given head, determine if there is a cycle in the linked list. Return true if there is a cycle, otherwise false.

Intersection of Two Linked Lists

Tue, 12 May 2026 00:00:00 GMT

Find the node where two singly linked lists intersect, or return null if they don't.

Majority Element

Tue, 12 May 2026 00:00:00 GMT

Given an array nums of size n, return the majority element that appears more than ⌊n/2⌋ times.

Happy Number

Tue, 12 May 2026 00:00:00 GMT

Write an algorithm to determine if a number n is happy. A happy number ends in 1 after repeatedly replacing it with the sum of squares of its digits.

Reverse Linked List

Tue, 12 May 2026 00:00:00 GMT

Reverse a singly linked list by changing the links between nodes.

Contains Duplicate

Tue, 12 May 2026 00:00:00 GMT

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

Palindrome Linked List

Tue, 12 May 2026 00:00:00 GMT

Given the head of a singly linked list, return true if it is a palindrome or false otherwise.

Valid Anagram

Tue, 12 May 2026 00:00:00 GMT

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

Longest Alternating Subarray

Tue, 12 May 2026 00:00:00 GMT

You are given a 0-indexed integer array nums. A subarray s of length m is called alternating if: - m > 1 - s₁ - s₀ = 1 - sᵢ₊₁ - sᵢ = (-1)ⁱ for 0 ≤ i < m - 1.

Move Zeroes

Tue, 12 May 2026 00:00:00 GMT

Move all zeros to the end of an array while maintaining the relative order of the non-zero elements.

Minimum Operations to Collect Elements

Tue, 12 May 2026 00:00:00 GMT

You are given an array nums of positive integers and an integer k.

Search Insert Position

Tue, 12 May 2026 00:00:00 GMT

Given a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

Earliest Time to Finish One Task

Tue, 12 May 2026 00:00:00 GMT

You are given an integer array `tasks`, where `tasks[i]` represents the time required to complete the i-th task.

Equal Score Substrings

Tue, 12 May 2026 00:00:00 GMT

The score of a character is its position in the alphabet (1-indexed). That is, 'a' has a score of 1, 'b' has a score of 2, ..., 'z' has a score of 26.

Diameter of Binary Tree

Tue, 12 May 2026 00:00:00 GMT

Find the length of the longest path between any two nodes in a binary tree.

Climbing Stairs

Tue, 12 May 2026 00:00:00 GMT

Count distinct ways to climb n steps taking 1 or 2 steps at a time.

Middle of the Linked List

Tue, 12 May 2026 00:00:00 GMT

Given the head of a singly linked list, return the middle node. If there are two middle nodes, return the second middle node.

Merge Sorted Array

Tue, 12 May 2026 00:00:00 GMT

Merge two sorted arrays nums1 and nums2 into nums1. The first array has enough space to hold all elements. Do not return anything, modify nums1 in-place.

Binary Tree Inorder Traversal

Tue, 12 May 2026 00:00:00 GMT

Given the root of a binary tree, return the inorder traversal of its nodes' values.

Divide Two Integers

Mon, 11 May 2026 00:00:00 GMT

Given two integers 'dividend' and 'divisor', divide two integers without using multiplication, division, and mod operator.

Minimum Depth of Binary Tree

Mon, 27 Apr 2026 00:00:00 GMT

Find the minimum depth of a binary tree, defined as the number of nodes along the shortest path from the root node down to the nearest leaf node.

Minimum Distance to the Target Element

Mon, 27 Apr 2026 00:00:00 GMT

Given an array, a start index, and a target value, find the minimum absolute distance between the start index and any index containing the target.

Two Out of Three

Mon, 27 Apr 2026 00:00:00 GMT

Given three integer arrays, return a sorted list of distinct values that appear in at least two of the arrays.

Pass the Pillow

Sun, 26 Apr 2026 00:00:00 GMT

Find which person holds the pillow after passing it back and forth in a line for a given time.

Merge Strings Alternately

Sat, 25 Apr 2026 00:00:00 GMT

Merge two strings by adding letters in alternating order, starting with word1. Append extra letters from the longer string to the end.

Longest Palindrome

Sat, 25 Apr 2026 00:00:00 GMT

Find the length of the longest palindrome that can be built using letters from a given string.

Substrings of Size Three with Distinct Characters

Thu, 23 Apr 2026 00:00:00 GMT

Count the number of substrings of length 3 with all distinct characters.

Transpose Matrix

Thu, 23 Apr 2026 00:00:00 GMT

Given a 2D integer array matrix, return the transpose of matrix. The transpose means flipping the matrix over its main diagonal.

Minimum Cost of Buying Candies With Discount

Wed, 22 Apr 2026 00:00:00 GMT

Sort costs descending to maximize the value of free candies, then sum the paid ones.

Minimum Common Value

Wed, 22 Apr 2026 00:00:00 GMT

Given two sorted arrays, find the smallest integer present in both.

Find Valid Emails

Tue, 21 Apr 2026 00:00:00 GMT

Filter user emails based on specific prefix, domain, and extension rules using SQL.

Find the K-or of an Array

Mon, 20 Apr 2026 00:00:00 GMT

Find the K-or of an array by checking each bit position and setting bits that appear in at least k elements.

Largest Perimeter Triangle

Sun, 19 Apr 2026 00:00:00 GMT

Given an integer array nums, return the largest perimeter of a triangle with a non-zero area, or 0 if impossible.

Score of a String

Fri, 17 Apr 2026 00:00:00 GMT

Calculate the sum of absolute differences between ASCII values of adjacent characters in a string.

XOR Operation in an Array

Wed, 15 Apr 2026 00:00:00 GMT

Given an integer n and an integer start, define an array nums where nums[i] = start + 2 * i. Return the bitwise XOR of all elements of nums.

Path Crossing

Wed, 15 Apr 2026 00:00:00 GMT

Given a path string, determine if you cross your own path at any point during the walk.

Number of Different Integers in a String

Wed, 15 Apr 2026 00:00:00 GMT

Count distinct integer values in a string containing digits and letters, ignoring leading zeros.

Generate Tag for Video Caption

Sun, 12 Apr 2026 00:00:00 GMT

Generate a video tag by taking the first letter of each word, capitalizing the first, and lowercasing the rest.

Allow One Function Call

Sat, 11 Apr 2026 00:00:00 GMT

Create a function that allows another function to be called only once, returning the cached result on subsequent calls.

Number of Beautiful Pairs

Wed, 08 Apr 2026 00:00:00 GMT

Count pairs (i,j) where first digit of nums[i] and last digit of nums[j] are coprime (gcd=1).

Smallest Pair With Different Frequencies

Tue, 07 Apr 2026 00:00:00 GMT

Find the lexicographically smallest pair of indices where the frequencies of the corresponding elements differ.

Widest Vertical Area Between Two Points Containing No Points

Mon, 06 Apr 2026 00:00:00 GMT

Given n points on a 2D plane, find the maximum width of a vertical area between two points that contains no other points.

Find Center of Star Graph

Mon, 06 Apr 2026 00:00:00 GMT

There is an undirected star graph consisting of n nodes labeled from 1 to n. Find the center node.

Maximum Strong Pair XOR I

Mon, 06 Apr 2026 00:00:00 GMT

Find the maximum XOR value of a strong pair (i, j) where nums[i] <= nums[j].

Array Reduce Transformation

Sun, 05 Apr 2026 00:00:00 GMT

Implement a reduce function that applies a given function cumulatively to array elements starting from an initial value.

Construct the Rectangle

Sat, 04 Apr 2026 00:00:00 GMT

Find the dimensions [L, W] of a rectangle with a given area such that the difference between length and width is minimized.

Find Resultant Array After Removing Anagrams

Thu, 02 Apr 2026 00:00:00 GMT

Remove words from the array that are anagrams of the previous word until no more removals are possible.

Filter Elements from Array

Thu, 02 Apr 2026 00:00:00 GMT

Given an array and a function, return a new array containing only the elements for which the function returns true.

Modify the Matrix

Thu, 02 Apr 2026 00:00:00 GMT

Given a matrix, replace every -1 with the maximum value in its respective column.

Second Minimum Node In a Binary Tree

Wed, 01 Apr 2026 00:00:00 GMT

Find the second smallest distinct value in a special binary tree where every parent node is smaller than its children.

Number of Days Between Two Dates

Tue, 31 Mar 2026 00:00:00 GMT

Calculate the absolute difference in days between two given dates in the format YYYY-MM-DD.

Find Champion I

Tue, 31 Mar 2026 00:00:00 GMT

Find the champion team in a tournament given a results matrix where 1 means the row team is stronger than the column team.

Count the Number of Incremovable Subarrays I

Mon, 30 Mar 2026 00:00:00 GMT

Count subarrays whose removal results in a strictly increasing array.

Longest Unequal Adjacent Groups Subsequence I

Sat, 28 Mar 2026 00:00:00 GMT

Find the longest subsequence of words where adjacent groups are unequal.

Transformed Array

Fri, 27 Mar 2026 00:00:00 GMT

Transform an array by adding each element to its neighbor based on sign, using original values.

Keyboard Row

Fri, 27 Mar 2026 00:00:00 GMT

Given an array of words, return the words that can be typed using letters of the alphabet on only one row of an American keyboard.

Sort the People

Thu, 26 Mar 2026 00:00:00 GMT

Sort people by their heights in descending order and return their names.

Reshape the Matrix

Thu, 26 Mar 2026 00:00:00 GMT

Reshape a 2D matrix into a new dimension while preserving the original data order.

Largest Number After Digit Swaps by Parity

Tue, 24 Mar 2026 00:00:00 GMT

You are given a positive integer num. You can swap two digits if they have the same parity. Return the largest number you can get.

Find Special Substring of Length K

Tue, 24 Mar 2026 00:00:00 GMT

Count the number of substrings of length k where all characters are identical.

Check Array Formation Through Concatenation

Mon, 23 Mar 2026 00:00:00 GMT

Determine if an array can be formed by concatenating arrays from a list, preserving internal order.

Make Array Zero by Subtracting Equal Amounts

Sun, 22 Mar 2026 00:00:00 GMT

Find the minimum number of operations to make all array elements zero by subtracting equal amounts from non-zero elements.

Destination City

Sat, 21 Mar 2026 00:00:00 GMT

Find the destination city in a list of paths where the destination has no outgoing path.

Drop Missing Data

Sat, 21 Mar 2026 00:00:00 GMT

Remove rows containing missing values from a DataFrame

Cells with Odd Values in a Matrix

Thu, 19 Mar 2026 00:00:00 GMT

Count odd-valued cells in an m x n matrix after incrementing all cells in specified rows and columns.

Find First Palindromic String in the Array

Thu, 19 Mar 2026 00:00:00 GMT

Given an array of strings, return the first string that reads the same forwards and backwards.

Find the Maximum Divisibility Score

Thu, 19 Mar 2026 00:00:00 GMT

Find the divisor with the maximum divisibility score from an array of numbers. Return the smallest divisor if there's a tie.

Find The Least Frequent Digit

Thu, 19 Mar 2026 00:00:00 GMT

Given an integer n, return the least frequent digit. If multiple digits have the same least frequency, return the smallest one.

Max Pair Sum in an Array

Tue, 17 Mar 2026 00:00:00 GMT

Find the maximum sum of a pair of numbers where the maximum digit of both numbers is the same.

Sign of the Product of an Array

Sun, 15 Mar 2026 00:00:00 GMT

Determine the sign of the product of an array of integers without calculating the actual product to avoid overflow.

Calculate Special Bonus

Fri, 13 Mar 2026 00:00:00 GMT

Calculate the bonus for employees based on their ID and name, excluding those with odd IDs or names starting with 'M'.

V-Rivals — Valorant Esports Platform

Thu, 12 Mar 2026 00:00:00 GMT

An award-winning competitive Valorant platform with real-time tournament brackets, Riot API stat syncing, Discord bot integration, and player scouting. Built with Next.js 15, Tailwind CSS 4 & Appwrite.

Excel Sheet Column Number

Wed, 11 Mar 2026 00:00:00 GMT

Given a string columnTitle representing the column title as it appears in an Excel sheet, return its corresponding column number.

Create a New Column

Wed, 11 Mar 2026 00:00:00 GMT

Write a solution to create a new column 'bonus' in a DataFrame by doubling the 'salary' values.

Available Captures for Rook

Wed, 11 Mar 2026 00:00:00 GMT

Count how many pawns a rook can capture in one move on an 8x8 chessboard.

Check if Word Equals Summation of Two Words

Tue, 10 Mar 2026 00:00:00 GMT

Check if the sum of numerical values of two words equals the numerical value of a target word.

Check if Numbers Are Ascending in a Sentence

Mon, 09 Mar 2026 00:00:00 GMT

Check if all numbers in a sentence are in strictly ascending order from left to right.

Design HashSet

Mon, 09 Mar 2026 00:00:00 GMT

Design a HashSet without using built-in hash table libraries. Implement add, remove, and contains operations.

Count Complete Tree Nodes

Sun, 08 Mar 2026 00:00:00 GMT

Given the root of a complete binary tree, return the number of nodes in the tree efficiently without traversing all nodes.

Longer Contiguous Segments of Ones than Zeros

Sat, 07 Mar 2026 00:00:00 GMT

Check if the longest contiguous segment of 1s is strictly longer than the longest contiguous segment of 0s in a binary string.

Rings and Rods

Sat, 07 Mar 2026 00:00:00 GMT

Count rods that have all three colored rings (red, green, blue) placed on them.

Check Whether Two Strings are Almost Equivalent

Fri, 06 Mar 2026 00:00:00 GMT

Check if two strings are almost equivalent by comparing character frequencies with a maximum difference of 3.

Meeting Rooms

Fri, 06 Mar 2026 00:00:00 GMT

Determine if a person could attend all meetings given an array of time intervals.

Add Strings

Wed, 04 Mar 2026 00:00:00 GMT

Given two non-negative integers num1 and num2 represented as strings, return the sum of num1 and num2 as a string.

Minimum Operations to Make Columns Strictly Increasing

Sun, 01 Mar 2026 00:00:00 GMT

You are given a matrix. Increment cells to make every column strictly increasing. Return the minimum operations.

Count Dominant Indices

Sun, 01 Mar 2026 00:00:00 GMT

Count the number of indices where the element is strictly greater than the sum of elements to its left and right.

Reverse Vowels of a String

Sat, 28 Feb 2026 00:00:00 GMT

Given a string s, reverse only all the vowels in the string and return it.

Advanced Level Pinterest Affiliate Marketing

Sat, 28 Feb 2026 00:00:00 GMT

An automated Make.com workflow that fetches Amazon products via RapidAPI, generates engaging Pinterest post content using OpenAI GPT-4o, and directly publishes to Pinterest boards.

Longest Subsequence With Limited Sum

Thu, 26 Feb 2026 00:00:00 GMT

Find the length of the longest subsequence of nums with sum less than or equal to each query.

Nim Game

Wed, 25 Feb 2026 00:00:00 GMT

Determine if you can win the Nim Game where you and a friend take turns removing 1-3 stones from a heap.

Concatenation of Array

Tue, 24 Feb 2026 00:00:00 GMT

Given an array nums, return an array ans where ans is the concatenation of nums with itself.

Count Pairs Of Similar Strings

Sat, 21 Feb 2026 00:00:00 GMT

Count pairs of strings that contain the same set of unique characters.

Maximum Containers on a Ship

Sat, 21 Feb 2026 00:00:00 GMT

Calculate the maximum number of containers that can fit on a ship given dimensions, allowing rotation.

Furthest Point From Origin

Tue, 17 Feb 2026 00:00:00 GMT

Calculate the maximum possible distance from the origin after moving left, right, or either direction.

Number of 1 Bits

Mon, 16 Feb 2026 00:00:00 GMT

Write a function that takes the binary representation of an unsigned integer and returns the number of '1' bits it has (also known as the Hamming weight).

Minimum Operations to Equalize Array

Sun, 15 Feb 2026 00:00:00 GMT

Find minimum bit flips to make all array elements equal.

Binary Tree Postorder Traversal

Sat, 14 Feb 2026 00:00:00 GMT

Given the root of a binary tree, return the postorder traversal of its nodes' values.

Relative Ranks

Sat, 14 Feb 2026 00:00:00 GMT

Assign ranks to athletes based on their scores with Gold, Silver, Bronze medals for top 3.

AI Blog Content Repurposer

Fri, 13 Feb 2026 00:00:00 GMT

An AI-powered engine that transforms blog URLs into viral social media assets (LinkedIn, Twitter, SEO, Video) using Google Gemini and Next.js.

Summary Ranges

Thu, 12 Feb 2026 00:00:00 GMT

You are given a sorted unique integer array nums. Return the smallest sorted list of ranges that cover all the numbers in the array exactly.

Missing Number

Thu, 12 Feb 2026 00:00:00 GMT

Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from the array.

Find Target Indices After Sorting Array

Tue, 10 Feb 2026 00:00:00 GMT

Find all indices where the element equals target after sorting the array in non-decreasing order.

Existence of a Substring in a String and Its Reverse

Tue, 10 Feb 2026 00:00:00 GMT

Check if a string contains a substring of length at least 2 that also appears in its reverse.

Reverse Only Letters

Sun, 08 Feb 2026 00:00:00 GMT

Given a string s, reverse the string while keeping all non-letter characters in their original positions.

Maximum Difference Between Adjacent Elements in a Circular Array

Thu, 05 Feb 2026 00:00:00 GMT

Find the maximum absolute difference between adjacent elements in a circular array.

Excel Sheet Column Title

Mon, 02 Feb 2026 00:00:00 GMT

Convert a given column number to its corresponding Excel column title as it appears in an Excel sheet.

Lexicographically Smallest Palindrome

Mon, 02 Feb 2026 00:00:00 GMT

You are given a string s. You can change any character to any other lowercase English letter. Return the lexicographically smallest palindrome you can make.

Primary Department for Each Employee

Fri, 30 Jan 2026 00:00:00 GMT

Find the primary department for each employee, prioritizing the 'Y' flag or the smallest department ID if no flag exists.

Count Prefixes of a Given String

Fri, 30 Jan 2026 00:00:00 GMT

Count how many strings in an array are prefixes of a target string.

Find the Peaks

Fri, 30 Jan 2026 00:00:00 GMT

Identify all peak indices in an array where a peak is strictly greater than its neighbors.

Check if All the Integers in a Range Are Covered

Thu, 29 Jan 2026 00:00:00 GMT

Determine if every integer in a given range is covered by at least one interval from a list of ranges.

Ugly Number

Thu, 29 Jan 2026 00:00:00 GMT

An ugly number is a positive integer whose prime factors are limited to 2, 3, and 5.

Find the Encrypted String

Tue, 27 Jan 2026 00:00:00 GMT

Encrypt a string by replacing each character with the character k positions ahead, wrapping around if necessary.

Two Sum IV - Input is a BST

Tue, 27 Jan 2026 00:00:00 GMT

Given a Binary Search Tree and a target number k, return true if there exist two elements in the BST such that their sum is equal to the given target.

Students and Examinations

Mon, 26 Jan 2026 00:00:00 GMT

Write a query to list all students, all subjects, and the count of exams attended by each student for each subject.

Sorting the Sentence

Sun, 25 Jan 2026 00:00:00 GMT

A sentence where each word has a trailing digit needs to be sorted based on that digit and reconstructed.

Maximum Difference Between Increasing Elements

Sun, 25 Jan 2026 00:00:00 GMT

Find the maximum difference nums[j] - nums[i] where i < j and nums[i] < nums[j].

Customer Placing the Largest Number of Orders

Sun, 25 Jan 2026 00:00:00 GMT

Find the customer who has placed the largest number of orders from the Orders table.

Minimum Number of Operations to Convert Time

Fri, 23 Jan 2026 00:00:00 GMT

Convert time from current to correct using minimum operations of adding 1, 5, 15, or 60 minutes.

Remove Letter To Equalize Frequency

Tue, 20 Jan 2026 00:00:00 GMT

Check if removing one character from a string can make the frequency of all remaining characters equal.

Flipping an Image

Mon, 19 Jan 2026 00:00:00 GMT

Given an n x n binary matrix image, flip the image horizontally, then invert it, and return the resulting image.

Next Greater Element I

Sat, 17 Jan 2026 00:00:00 GMT

Find the next greater element for each element in nums1 based on its position in nums2.

Design an Ordered Stream

Fri, 16 Jan 2026 00:00:00 GMT

Implement a data structure that inserts (id, value) pairs and returns consecutive chunks of values starting from a pointer.

Count of Matches in Tournament

Fri, 16 Jan 2026 00:00:00 GMT

Given n teams, count the total matches in a single-elimination tournament where each match eliminates one team.

Count Elements With Maximum Frequency

Fri, 16 Jan 2026 00:00:00 GMT

Count the total frequency of elements in an array that appear the maximum number of times.

Check if Any Element Has Prime Frequency

Fri, 16 Jan 2026 00:00:00 GMT

Determine if any element in an array appears a prime number of times.

Find Pivot Index

Fri, 16 Jan 2026 00:00:00 GMT

Given an array of integers nums, calculate the pivot index where the sum of all the numbers to the left is equal to the sum of all the numbers to the right.

Remove Zeros in Decimal Representation

Thu, 15 Jan 2026 00:00:00 GMT

Given an integer n, return the integer obtained by removing all trailing zeros from its decimal representation.

Bitcoin EMA Crossover Alert System

Thu, 15 Jan 2026 00:00:00 GMT

A robust n8n workflow that calculates Exponential Moving Average (EMA) crossovers (9/21 periods) for Bitcoin across multiple timeframes, persisting state in Google Sheets and dispatching real-time trading signals via Telegram.

Count Hills and Valleys in an Array

Wed, 14 Jan 2026 00:00:00 GMT

Count indices in an array that are strictly greater or smaller than their neighbors, skipping consecutive duplicates.

Assign Cookies

Tue, 13 Jan 2026 00:00:00 GMT

Maximize the number of content children by assigning cookies that satisfy their minimum size requirements.

Daily Leads and Partners

Mon, 12 Jan 2026 00:00:00 GMT

Count the number of unique leads and partners for each day.

Check Distances Between Same Letters

Mon, 12 Jan 2026 00:00:00 GMT

Check if distances between same letters in a string match a given distance array.

First Matching Character From Both Ends

Mon, 12 Jan 2026 00:00:00 GMT

Find the first character that matches when comparing the string from the start and end moving inwards.

Valid Parentheses

Sat, 10 Jan 2026 00:00:00 GMT

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

Count Special Quadruplets

Fri, 09 Jan 2026 00:00:00 GMT

Given an array, count quadruplets (a,b,c,d) where a

Most Visited Sector in a Circular Track

Thu, 08 Jan 2026 00:00:00 GMT

Given a circular track with n sectors and an array of rounds, find the most visited sectors after completing all rounds.

Check If Digits Are Equal in String After Operations I

Thu, 08 Jan 2026 00:00:00 GMT

Determine if all digits in a string can be made equal by repeatedly replacing a digit with its left neighbor if they differ.

Hamming Distance

Wed, 07 Jan 2026 00:00:00 GMT

The Hamming distance between two integers is the number of positions at which the corresponding bits are different.

Separate the Digits in an Array

Tue, 06 Jan 2026 00:00:00 GMT

Given an array of positive integers, return an array with each integer's digits separated in order.

Neither Minimum nor Maximum

Tue, 06 Jan 2026 00:00:00 GMT

Find an integer in the array that is neither the minimum nor the maximum value.

Three Divisors

Mon, 05 Jan 2026 00:00:00 GMT

Given an integer n, return true if n has exactly three positive divisors, otherwise return false.

Find a Corresponding Node of a Binary Tree in a Clone of That Tree

Sat, 03 Jan 2026 00:00:00 GMT

Given two binary trees, original and cloned, and a node in the original, return the corresponding node in the cloned tree.

Maximum Enemy Forts That Can Be Captured

Sat, 03 Jan 2026 00:00:00 GMT

Find the maximum distance between your fort (1) and an enemy fort (-1) passing only through empty forts (0).

Construct the Minimum Bitwise Array I

Thu, 01 Jan 2026 00:00:00 GMT

Given an array of positive integers, find the smallest x for each element such that x & (x + 1) equals the element.

Unique Number of Occurrences

Wed, 31 Dec 2025 00:00:00 GMT

Check if the frequency of every value in an array is unique.

Number of Employees Who Met the Target

Wed, 31 Dec 2025 00:00:00 GMT

Count how many employees worked at least the target number of hours.

Smallest Index With Equal Value

Tue, 30 Dec 2025 00:00:00 GMT

Find the smallest index i where i % 10 equals nums[i], or return -1.

Longest Nice Substring

Mon, 29 Dec 2025 00:00:00 GMT

Find the longest substring where every letter appears in both uppercase and lowercase forms.

Largest 3-Same-Digit Number in String

Mon, 29 Dec 2025 00:00:00 GMT

You are given a string num representing a large integer. Return the largest-valued good integer as a string or an empty string if no such integer exists.

Find Subarrays With Equal Sum

Fri, 26 Dec 2025 00:00:00 GMT

Check if there exist two distinct subarrays of length 2 with equal sum in an array.

Find Total Time Spent by Each Employee

Thu, 25 Dec 2025 00:00:00 GMT

Calculate the total time in seconds spent by each employee per day based on their in and out times.

Construct Uniform Parity Array I

Thu, 25 Dec 2025 00:00:00 GMT

Construct an array of length n where elements match the parity of their index, using values from 1 to m.

Minimum Index Sum of Two Lists

Thu, 25 Dec 2025 00:00:00 GMT

Given two string arrays, find the common strings with the smallest sum of their indices.

Minimum Sum of Mountain Triplets I

Tue, 23 Dec 2025 00:00:00 GMT

Find the minimum sum of a mountain triplet (i, j, k) where i < j < k, nums[i] < nums[j], and nums[k] < nums[j].

Apply Transform Over Each Element in Array

Mon, 22 Dec 2025 00:00:00 GMT

Given an array and a function, return a new array where each element is the result of applying the function to the original element and its index.

Fibonacci Number

Mon, 22 Dec 2025 00:00:00 GMT

The Fibonacci numbers form a sequence where each number is the sum of the two preceding ones, starting from 0 and 1. Given n, return F(n).

Running Sum of 1d Array

Sun, 21 Dec 2025 00:00:00 GMT

Given an array nums, return the running sum of the array where runningSum[i] = sum(nums[0]...nums[i]).

Keep Multiplying Found Values by Two

Sun, 21 Dec 2025 00:00:00 GMT

Find original in nums, multiply by 2, repeat until not found. Return final value.

Valid Digit Number

Sun, 21 Dec 2025 00:00:00 GMT

Check if a string consists only of digits and does not have leading zeros.

Check If Two String Arrays are Equivalent

Fri, 19 Dec 2025 00:00:00 GMT

Given two string arrays, determine if they represent the same string when concatenated.

Smallest Stable Index I

Fri, 19 Dec 2025 00:00:00 GMT

Find the smallest index i where nums[i] equals the sum of elements before it.

Average Selling Price

Wed, 17 Dec 2025 00:00:00 GMT

Calculate the average selling price for each product based on unit sales and applicable price ranges.

Implement Stack using Queues

Wed, 17 Dec 2025 00:00:00 GMT

Implement a last-in-first-out (LIFO) stack using only two queues.

Counter

Tue, 16 Dec 2025 00:00:00 GMT

Create a counter function that returns incrementing values starting from a given integer.

Timeout Cancellation

Tue, 16 Dec 2025 00:00:00 GMT

Implement a cancellable timeout function that executes a given function after a delay, with the ability to cancel the execution.

Minimum Time Visiting All Points

Mon, 15 Dec 2025 00:00:00 GMT

Calculate the minimum time to visit all points in order on a 2D plane, moving one unit per second in any of 8 directions.

Contains Duplicate II

Mon, 15 Dec 2025 00:00:00 GMT

Given an integer array nums and an integer k, return true if there are two distinct indices i and j such that nums[i] == nums[j] and abs(i - j) <= k.

Sales Person

Mon, 15 Dec 2025 00:00:00 GMT

Find all sales people who did not have any orders with company named RED

Replace All ?'s to Avoid Consecutive Repeating Characters

Sun, 14 Dec 2025 00:00:00 GMT

Replace all '?' characters in a string with lowercase letters so no two consecutive characters are the same.

Merge Two Binary Trees

Wed, 10 Dec 2025 00:00:00 GMT

Merge two binary trees by summing overlapping nodes and using non-null nodes for non-overlapping parts.

AI Crypto Predictor & Trading Assistant

Wed, 10 Dec 2025 00:00:00 GMT

An advanced n8n automation that acts as an AI-driven trading assistant. It ingests live market data and news, performs AI sentiment analysis, and uses Google Gemini to generate highly detailed, multi-timeframe trading signals delivered via Telegram.

Largest Odd Number in String

Tue, 09 Dec 2025 00:00:00 GMT

Find the largest odd integer substring in a given numeric string.

Number of Even and Odd Bits

Sun, 07 Dec 2025 00:00:00 GMT

Count the number of 1s at even and odd positions in the binary representation of a given positive integer.

Make Three Strings Equal

Sat, 06 Dec 2025 00:00:00 GMT

Find minimum operations to make three strings equal by deleting from the end.

Greatest English Letter in Upper and Lower Case

Thu, 04 Dec 2025 00:00:00 GMT

Find the greatest English letter that appears in both uppercase and lowercase in a given string.

Counter II

Wed, 03 Dec 2025 00:00:00 GMT

Create a counter object with increment, decrement, and reset functions using closures.

Array Wrapper

Tue, 02 Dec 2025 00:00:00 GMT

Create a class that wraps an array and provides string representation and addition operations.

Count Residue Prefixes

Tue, 02 Dec 2025 00:00:00 GMT

Count the number of prefixes of a numeric string that are divisible by a given integer.

Teemo Attacking

Mon, 01 Dec 2025 00:00:00 GMT

Calculate the total time Ashe is poisoned based on Teemo's attack timings and poison duration.

Sqrt(x)

Mon, 01 Dec 2025 00:00:00 GMT

Given a non-negative integer x, return the square root of x rounded down to the nearest integer.

Sort Array By Parity

Mon, 01 Dec 2025 00:00:00 GMT

Move all even integers to the beginning of the array followed by all odd integers.

Recyclable and Low Fat Products

Sun, 30 Nov 2025 00:00:00 GMT

Find product IDs for products that are both recyclable and low fat.

Maximize Sum of At Most K Distinct Elements

Sun, 30 Nov 2025 00:00:00 GMT

Given an array nums and integer k, find the maximum sum of a subset containing at most k distinct elements.

Sort By

Sat, 29 Nov 2025 00:00:00 GMT

Implement a function to sort an array of objects based on a function that returns a value to sort by.

Trionic Array I

Fri, 28 Nov 2025 00:00:00 GMT

Check if an array is trionic: length 3, distinct elements, and sum of first two equals the third.

Difference Between Element Sum and Digit Sum of an Array

Mon, 24 Nov 2025 00:00:00 GMT

Calculate the absolute difference between the sum of array elements and the sum of their individual digits.

Uncommon Words from Two Sentences

Mon, 24 Nov 2025 00:00:00 GMT

A sentence is a string of single-space separated words. Find all words that appear exactly once in one of the sentences, and do not appear in the other sentence.

Make Two Arrays Equal by Reversing Subarrays

Sun, 23 Nov 2025 00:00:00 GMT

Check if two arrays can be made equal by reversing subarrays. Since any permutation is possible, we just need to check if they have the same elements.

Add Two Promises

Sat, 22 Nov 2025 00:00:00 GMT

Given two promises that resolve to numbers, return a promise that resolves to their sum.

Count Asterisks

Thu, 20 Nov 2025 00:00:00 GMT

Count asterisks in a string, excluding those between pairs of vertical bars.

Find Most Frequent Vowel and Consonant

Thu, 20 Nov 2025 00:00:00 GMT

Given a string, find the most frequent vowel and consonant. Return the result based on frequency and lexicographical order.

Number of Common Factors

Tue, 18 Nov 2025 00:00:00 GMT

Given two positive integers a and b, return the number of common factors of a and b.

Make a Square with the Same Color

Sat, 15 Nov 2025 00:00:00 GMT

Determine if you can change one cell in a 3x3 grid to form a 2x2 square of uniform color.

Find the Difference

Sat, 15 Nov 2025 00:00:00 GMT

You are given two strings s and t. String t is generated by random shuffling string s and then adding one more letter at a random position. Return the letter that was added to t.

Ant on the Boundary

Wed, 12 Nov 2025 00:00:00 GMT

An ant moves left or right based on an array of integers. Return the number of times it returns to the boundary (position 0) after the first move.

Rearrange Characters to Make Target String

Sat, 08 Nov 2025 00:00:00 GMT

Given two strings s and target, find the maximum number of copies of target that can be formed by rearranging characters from s.

Customer Who Visited but Did Not Make Any Transactions

Thu, 06 Nov 2025 00:00:00 GMT

Find customers who visited the mall but did not make any transactions using SQL queries.

Check if Grid Satisfies Conditions

Wed, 05 Nov 2025 00:00:00 GMT

Check if all cells in each row have the same value and all cells in each column have different values.

Trim Trailing Vowels

Wed, 05 Nov 2025 00:00:00 GMT

Remove all trailing vowels from a given string. Vowels include both lowercase and uppercase letters.

DDC API AI Chat & Image Assistant

Wed, 05 Nov 2025 00:00:00 GMT

A versatile n8n chat automation that routes user messages to an external Language Model (GPT-4.1-mini equivalent) for conversational responses, and to FLUX.1 for dynamic, high-quality image generation.

Check If String Is a Prefix of Array

Tue, 04 Nov 2025 00:00:00 GMT

Given a string s and an array of strings words, check if s can be formed by concatenating some prefix of words in order.

Lucky Numbers in a Matrix

Sun, 02 Nov 2025 00:00:00 GMT

Find all lucky numbers in a matrix where a number is the minimum in its row and maximum in its column.

Shuffle the Array

Fri, 31 Oct 2025 00:00:00 GMT

Given an array of 2n elements, rearrange it to [x1, y1, x2, y2, ...] where the first half is x and second half is y.

Find Followers Count

Fri, 31 Oct 2025 00:00:00 GMT

Count the number of followers for each user from the Followers table.

Add Digits

Fri, 31 Oct 2025 00:00:00 GMT

Given an integer num, repeatedly add all its digits until the result has only one digit.

Find Winner on a Tic Tac Toe Game

Thu, 30 Oct 2025 00:00:00 GMT

Determine the winner of a Tic Tac Toe game given a sequence of moves, or if the game is a draw or pending.

Maximum Value of an Ordered Triplet I

Thu, 30 Oct 2025 00:00:00 GMT

Find the maximum value of (nums[i] - nums[j]) * nums[k] where i < j < k in an array.

The Employee That Worked on the Longest Task

Tue, 28 Oct 2025 00:00:00 GMT

Find the employee who worked on the longest single task given logs of task completion times.

Delete Duplicate Emails

Sun, 26 Oct 2025 00:00:00 GMT

Write a SQL query to delete all duplicate email entries in a table, keeping only the one with the smallest Id.

Merge Two 2D Arrays by Summing Values

Sun, 26 Oct 2025 00:00:00 GMT

Merge two 2D arrays by summing values for matching IDs and return the result sorted by ID.

Longest Even Odd Subarray With Threshold

Sun, 26 Oct 2025 00:00:00 GMT

Find the longest subarray where elements alternate between even and odd and all elements are at most threshold.

Repeated Substring Pattern

Sun, 26 Oct 2025 00:00:00 GMT

Given a string s, check if it can be constructed by taking a substring of it and appending multiple copies of the substring together.

Divide an Array Into Subarrays With Minimum Cost I

Fri, 24 Oct 2025 00:00:00 GMT

Divide array into 3 subarrays where cost is first element of each subarray. Find minimum total cost.

Smallest Range I

Fri, 24 Oct 2025 00:00:00 GMT

Find the minimum possible difference between max and min elements after adding/subtracting at most k from each element.

Buy Two Chocolates

Thu, 23 Oct 2025 00:00:00 GMT

Given an array of chocolate prices and money, find the leftover money after buying the two cheapest chocolates, or return the original money if not possible.

Sales Analysis III

Wed, 22 Oct 2025 00:00:00 GMT

Report products sold only in 2019 and not in 2020.

Increasing Decreasing String

Wed, 22 Oct 2025 00:00:00 GMT

Reorder string characters by repeatedly picking the smallest available character, then the largest, until empty.

Restore Finishing Order

Wed, 22 Oct 2025 00:00:00 GMT

Given an array where each element represents the number of runners before that runner, restore the finishing order.

Goat Latin

Wed, 22 Oct 2025 00:00:00 GMT

Convert a sentence to Goat Latin by moving consonants, adding suffixes, and appending 'a's based on word index.

Backspace String Compare

Wed, 22 Oct 2025 00:00:00 GMT

Given two strings s and t, return true if they are equal when both are typed into empty text editors. '#' means a backspace character.

Compliant Site Content Fetcher

Mon, 20 Oct 2025 00:00:00 GMT

An n8n automation template designed for ethical web scraping. It automatically parses `robots.txt` files to ensure compliance before fetching and extracting data (JSON, RSS, or HTML), featuring built-in exponential backoff for rate limiting.

N-Repeated Element in Size 2N Array

Sat, 18 Oct 2025 00:00:00 GMT

In an array of size 2N with N+1 unique elements, find the element that is repeated N times.

Maximum Area of Longest Diagonal Rectangle

Thu, 16 Oct 2025 00:00:00 GMT

Find the area of the rectangle with the longest diagonal length. If multiple rectangles have the same longest diagonal, return the maximum area among them.

Find Mode in Binary Search Tree

Thu, 16 Oct 2025 00:00:00 GMT

Given the root of a BST with duplicates, return the mode(s) (most frequently occurring elements) in the tree.

Employees With Missing Information

Mon, 13 Oct 2025 00:00:00 GMT

Find employees who are missing information in either the Employees table or the Salaries table.

Prime Number of Set Bits in Binary Representation

Sun, 12 Oct 2025 00:00:00 GMT

Count numbers in range [left, right] with prime number of 1s in binary representation.

Smallest Index With Digit Sum Equal to Index

Sat, 11 Oct 2025 00:00:00 GMT

Find the smallest index i where the sum of digits of i equals nums[i].

Number of Valid Words in a Sentence

Fri, 10 Oct 2025 00:00:00 GMT

Count valid words in a sentence where words must follow specific rules for hyphens and punctuation.

Flip Square Submatrix Vertically

Wed, 08 Oct 2025 00:00:00 GMT

Flip a specific square submatrix within a grid vertically by reversing the order of its rows.

Final Array State After K Multiplication Operations I

Tue, 07 Oct 2025 00:00:00 GMT

Perform k operations replacing the smallest element with its product by multiplier.

Squares of a Sorted Array

Tue, 07 Oct 2025 00:00:00 GMT

Given an integer array sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.

Find Words Containing Character

Mon, 06 Oct 2025 00:00:00 GMT

Return indices of words in an array that contain a given character.

Reformat Phone Number

Sun, 05 Oct 2025 00:00:00 GMT

Reformat a phone number string by removing non-digits and grouping into blocks of 3, with special handling for the last block.

Matrix Diagonal Sum

Fri, 03 Oct 2025 00:00:00 GMT

Given a square matrix, return the sum of the matrix diagonals, excluding the center element if counted twice.

Minimum String Length After Removing Substrings

Wed, 01 Oct 2025 00:00:00 GMT

Remove 'AB' and 'CD' substrings repeatedly from a string and return the minimum possible length.

Design HashMap

Wed, 01 Oct 2025 00:00:00 GMT

Design a HashMap without using built-in hash table libraries, implementing put, get, and remove methods.

Patients With a Condition

Mon, 29 Sep 2025 00:00:00 GMT

Find patients with Type I Diabetes condition codes starting with DIAB1

Semi-Ordered Permutation

Mon, 29 Sep 2025 00:00:00 GMT

Find minimum adjacent swaps to move 1 to front and n to end in a permutation.

Binary Search

Mon, 29 Sep 2025 00:00:00 GMT

Given a sorted array of integers and a target value, return the index of the target if it exists, otherwise return -1.

Fill Missing Data

Sun, 28 Sep 2025 00:00:00 GMT

Replace missing quantity values in a DataFrame with the median of existing quantities, rounding to the nearest integer.

Decompress Run-Length Encoded List

Wed, 24 Sep 2025 00:00:00 GMT

Decompress a run-length encoded list by expanding frequency-value pairs into a flat array.

Convert Integer to the Sum of Two No-Zero Integers

Wed, 24 Sep 2025 00:00:00 GMT

Find two positive integers without any zero digits that sum to the given integer n.

The K Weakest Rows in a Matrix

Wed, 24 Sep 2025 00:00:00 GMT

Find the k weakest rows in a binary matrix where each row is sorted with 1s before 0s.

Slowest Key

Wed, 24 Sep 2025 00:00:00 GMT

Determine the key with the longest duration from release times and key pressed sequence, returning the lexicographically largest key on ties.

Is Subsequence

Mon, 22 Sep 2025 00:00:00 GMT

Check if string s is a subsequence of string t by deleting some characters without changing the order.

Valid Palindrome II

Fri, 19 Sep 2025 00:00:00 GMT

Given a string s, return true if the s can be palindrome after deleting at most one character from it.

Find the Index of the First Occurrence in a String

Thu, 18 Sep 2025 00:00:00 GMT

Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

Minimum Operations to Exceed Threshold Value I

Wed, 17 Sep 2025 00:00:00 GMT

Count the number of elements in an array that are strictly less than a given threshold k.

Find the Integer Added to Array I

Wed, 17 Sep 2025 00:00:00 GMT

You are given two integer arrays nums1 and nums2. Find the integer x added to every element of nums1 to make it equal to nums2.

Remove Element

Tue, 16 Sep 2025 00:00:00 GMT

Given an integer array nums and an integer val, remove all occurrences of val in nums in-place. The order of the elements may be changed. Then return the number of elements in nums which are not equal to val. Consider the number of elements in nums which are not equal to val be k, to get accepted, you need to do the following things: - Change the array nums such that the first k elements of nums contain the elements which are not equal to val. The remaining elements of nums are not important as well as the size of nums. - Return k.

Remove Duplicates from Sorted Array

Mon, 15 Sep 2025 00:00:00 GMT

Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same. Then return the number of unique elements in nums. Consider the number of unique elements of nums to be k, the array nums should be modified such that the first k elements contain the unique elements in the order they were originally present. The rest of the elements are irrelevant. Return k.

Largest Even Number

Mon, 15 Sep 2025 00:00:00 GMT

Given a string of digits, rearrange them to form the largest possible even number.

Delta EMA Order Placer

Mon, 15 Sep 2025 00:00:00 GMT

An algorithmic trading tool that automates crypto order execution on Delta Exchange based on Exponential Moving Average (EMA) crossovers.

Reverse Nodes in k-Group

Sun, 14 Sep 2025 00:00:00 GMT

Given the head of a linked list, reverse the nodes of the list k at a time, and return the modified list. k is a positive integer and is less than or equal to the length of the list. If the number of nodes is not a multiple of k then left-out nodes in the end should remain as it is. You may not alter the values in the list's nodes, only nodes themselves may be changed.

Minimum Moves to Equal Array Elements III

Sun, 14 Sep 2025 00:00:00 GMT

Find the minimum moves to equalize array elements by changing at most k elements to any value.

Three Consecutive Odds

Sat, 13 Sep 2025 00:00:00 GMT

Given an integer array arr, return true if there are three consecutive odd numbers in the array. Otherwise, return false.

Merge k Sorted Lists

Fri, 12 Sep 2025 00:00:00 GMT

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list and return it.

Swap Nodes in Pairs

Fri, 12 Sep 2025 00:00:00 GMT

Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)

Telegram Subscriber Onboarding System

Fri, 12 Sep 2025 00:00:00 GMT

An automated n8n workflow designed to onboard new users to a Telegram bot. Captures dynamic chat context upon message receipt, checks an external Google Sheets database to prevent duplicate entries, and dispatches personalized welcome messages.

Lexicographically Smallest String After a Swap

Thu, 11 Sep 2025 00:00:00 GMT

Find the lexicographically smallest string by swapping characters with adjacent ASCII values.

Remove Nth Node From End of List

Wed, 10 Sep 2025 00:00:00 GMT

Given the head of a linked list, remove the nth node from the end of the list and return its head.

Merge Two Sorted Lists

Wed, 10 Sep 2025 00:00:00 GMT

You are given the heads of two sorted linked lists list1 and list2. Merge the two lists into one sorted list by splicing together the nodes of the first two lists. Return the head of the merged linked list.

Longest Common Prefix

Tue, 09 Sep 2025 00:00:00 GMT

Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "".

3Sum

Tue, 09 Sep 2025 00:00:00 GMT

Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0. Notice that the solution set must not contain duplicate triplets.

3Sum Closest

Tue, 09 Sep 2025 00:00:00 GMT

Given an integer array nums of length n and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the three integers. You may assume that each input would have exactly one solution.

Letter Combinations of a Phone Number

Tue, 09 Sep 2025 00:00:00 GMT

Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order. A mapping of digits to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.

Find the Distinct Difference Array

Tue, 09 Sep 2025 00:00:00 GMT

Calculate an array where each element is the count of distinct numbers in the prefix minus the count of distinct numbers in the suffix.

Account Balance After Rounded Purchase

Tue, 09 Sep 2025 00:00:00 GMT

Calculate the remaining account balance after a purchase is rounded to the nearest multiple of 10.

Regular Expression Matching

Mon, 08 Sep 2025 00:00:00 GMT

Given an input string (s) and a pattern (p), implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial).

Container With Most Water

Mon, 08 Sep 2025 00:00:00 GMT

You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]). Find two lines that together with the x-axis form a container, such that the container contains the most water. Return the maximum amount of water a container can store. Notice that you may not slant the container.

Integer to Roman

Mon, 08 Sep 2025 00:00:00 GMT

Seven different symbols represent Roman numerals with the following values: Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 Roman numerals are formed by appending the conversions of decimal place values from highest to lowest. Converting a decimal place value into a Roman numeral has the following rules: If the value does not start with 4 or 9, select the symbol of the maximal value that can be subtracted from the input, append that symbol to the result, subtract its value, and convert the remainder to a Roman numeral. If the value starts with 4 or 9 use the subtractive form representing one symbol subtracted from the following symbol, for example, 4 is 1 (I) less than 5 (V): IV and 9 is 1 (I) less than 10 (X): IX. Only the following subtractive forms are used: 4 (IV), 9 (IX), 40 (XL), 90 (XC), 400 (CD) and 900 (CM). Only powers of 10 (I, X, C, M) can be appended consecutively at most 3 times to represent multiples of 10. You cannot append 5 (V), 50 (L), or 500 (D) multiple times. If you need to append a symbol 4 times use the subtractive form. Given an integer, convert it to a Roman numeral.

Roman to Integer

Mon, 08 Sep 2025 00:00:00 GMT

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. For example, 2 is written as II in Roman numeral, just two ones added together. 12 is written as XII, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II. Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used: I can be placed before V (5) and X (10) to make 4 and 9. X can be placed before L (50) and C (100) to make 40 and 90. C can be placed before D (500) and M (1000) to make 400 and 900. Given a roman numeral, convert it to an integer.

Zigzag Conversion

Mon, 08 Sep 2025 00:00:00 GMT

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows. Write the code that will take a string and make this conversion given a number of rows.

Reverse Integer

Mon, 08 Sep 2025 00:00:00 GMT

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-2^31, 2^31 - 1], then return 0. Assume the environment does not allow you to store 64-bit integers (signed or unsigned).

String to Integer (atoi)

Mon, 08 Sep 2025 00:00:00 GMT

Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer (similar to C/C++'s atoi function). The algorithm for myAtoi(string s) is as follows: 1. Read in and ignore any leading whitespace. 2. Check if the next character (if not already at the end of the string) is '-' or '+'. Read this character in if it is either. This determines if the final result is negative or positive respectively. If neither is present, assume the result is positive. 3. Read in next the characters until the next non-digit character or the end of the input is reached. The rest of the string is ignored. 4. Convert these digits into an integer. If no digits were read, then the integer is 0. Change the sign as necessary. 5. If the integer is out of the 32-bit signed integer range [-2^31, 2^31 - 1], then clamp the integer so that it remains in the range. Specifically, integers less than -2^31 should be clamped to -2^31, and integers greater than 2^31 - 1 should be clamped to 2^31 - 1. Return the integer as the final result.

Palindrome Number

Mon, 08 Sep 2025 00:00:00 GMT

Given an integer x, return true if x is a palindrome, and false otherwise.

Two Sum

Sun, 07 Sep 2025 00:00:00 GMT

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order.

Sum of All Odd Length Subarrays

Sun, 07 Sep 2025 00:00:00 GMT

Given an array of positive integers, return the sum of all possible odd-length subarrays of the array.

Add Two Numbers

Sun, 07 Sep 2025 00:00:00 GMT

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list. You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Longest Substring Without Repeating Characters

Sun, 07 Sep 2025 00:00:00 GMT

Given a string s, find the length of the longest substring without repeating characters.

Median of Two Sorted Arrays

Sun, 07 Sep 2025 00:00:00 GMT

Given two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

Longest Palindromic Substring

Sun, 07 Sep 2025 00:00:00 GMT

Given a string s, return the longest palindromic substring in s.

Count Distinct Numbers on Board

Thu, 04 Sep 2025 00:00:00 GMT

Given a positive integer n, return the number of distinct numbers on the board after performing operations.

Minimum Number of Operations to Make Elements in Array Distinct

Wed, 03 Sep 2025 00:00:00 GMT

Calculate the minimum removals needed so all remaining elements in the array are unique.

Find Users with High Token Usage

Wed, 03 Sep 2025 00:00:00 GMT

Find users whose total token usage exceeds a given threshold using aggregation.

Tenth Line

Mon, 01 Sep 2025 00:00:00 GMT

Given a text file file.txt, print just the 10th line of the file.

Find Customer Referee

Mon, 01 Sep 2025 00:00:00 GMT

Find all customers who are not referred by customer with id 2

Robot Return to Origin

Mon, 01 Sep 2025 00:00:00 GMT

Determine if a robot returns to the origin after a sequence of moves represented by a string of characters 'U', 'D', 'L', 'R'.

Minimum Amount of Time to Fill Cups

Sun, 31 Aug 2025 00:00:00 GMT

Find the minimum time to fill cups of different types when you can fill up to 2 cups per second.

Calculate Delayed Arrival Time

Sat, 30 Aug 2025 00:00:00 GMT

Given arrival time and delay, calculate the new time in 24-hour format.

Maximum Difference Between Even and Odd Frequency I

Fri, 29 Aug 2025 00:00:00 GMT

Find the maximum difference between the sum of even frequencies and sum of odd frequencies of characters in a string.

Array Partition

Fri, 29 Aug 2025 00:00:00 GMT

Maximize the sum of minimums of pairs formed from an array of 2n integers.

Minimum Bit Flips to Convert Number

Wed, 27 Aug 2025 00:00:00 GMT

Find the minimum number of bit flips required to convert one integer to another by comparing their binary representations.

Shortest Distance to Target String in a Circular Array

Sat, 23 Aug 2025 00:00:00 GMT

Find the minimum moves to reach a target string in a circular array from a starting index.

Unity WebGL CI/CD Pipeline

Fri, 22 Aug 2025 00:00:00 GMT

An automated DevOps workflow for building and deploying Unity WebGL games directly to GitHub Pages using GitHub Actions.

To Be Or Not To Be

Thu, 21 Aug 2025 00:00:00 GMT

Implement an expect function that returns an object with toBe and notToBe methods for value comparison.

Most Frequent Number Following Key In an Array

Mon, 18 Aug 2025 00:00:00 GMT

Find the number that appears most frequently immediately after a given key in an array.

Maximum Repeating Substring

Sun, 17 Aug 2025 00:00:00 GMT

Find the maximum k such that word repeated k times is a substring of sequence.

Employees Earning More Than Their Managers

Sun, 17 Aug 2025 00:00:00 GMT

Find all employees who earn more than their direct managers using SQL self-joins.

Length of Last Word

Sun, 17 Aug 2025 00:00:00 GMT

Given a string s, return the length of the last word in the string.

Find Common Elements Between Two Arrays

Sat, 16 Aug 2025 00:00:00 GMT

Count elements in each array that also appear in the other array.

Sum of Unique Elements

Fri, 15 Aug 2025 00:00:00 GMT

Return the sum of all unique elements in an array where unique elements appear exactly once.

Check If It Is a Straight Line

Thu, 14 Aug 2025 00:00:00 GMT

Given coordinates of points, determine if they all lie on a straight line in the XY plane.

Rank Transform of an Array

Wed, 13 Aug 2025 00:00:00 GMT

Replace each element with its rank based on relative magnitude, starting from 1.

Number of Strings That Appear as Substrings in Word

Wed, 13 Aug 2025 00:00:00 GMT

Given an array of strings patterns and a string word, return the number of strings in patterns that are substrings of word.

Buddy Strings

Sat, 09 Aug 2025 00:00:00 GMT

Given two strings s and goal, return true if you can swap two letters in s so the result is equal to goal.

Find the Middle Index in Array

Thu, 07 Aug 2025 00:00:00 GMT

Find the leftmost index where the sum of elements to the left equals the sum of elements to the right.

Find Missing Elements

Thu, 07 Aug 2025 00:00:00 GMT

Given two arrays, find all elements in the first array that are not present in the second array.

Reformat Department Table

Wed, 06 Aug 2025 00:00:00 GMT

Pivot the Department table to display monthly revenue in columns.

Find the K-Beauty of a Number

Wed, 06 Aug 2025 00:00:00 GMT

Count the number of substrings of length k in num that are divisors of num.

Fruits Into Baskets II

Wed, 06 Aug 2025 00:00:00 GMT

Find the maximum number of fruits you can pick given you have two baskets and each basket can hold only one type of fruit.

Majority Frequency Characters

Wed, 06 Aug 2025 00:00:00 GMT

Find the character that appears more than half the time in a string using counting or voting algorithms.

Shortest Distance to a Character

Wed, 06 Aug 2025 00:00:00 GMT

Given a string and a character, find the shortest distance from each character to the target character.

Min Max Game

Mon, 04 Aug 2025 00:00:00 GMT

Apply min-max operations on an array until only one element remains.

Maximum Number of Balloons

Sun, 03 Aug 2025 00:00:00 GMT

Given a string text, find the maximum number of times you can form the word 'balloon' using its characters.

Count Symmetric Integers

Sat, 02 Aug 2025 00:00:00 GMT

Count integers in a range where the sum of the first half of digits equals the sum of the second half.

Maximum Height of a Triangle

Fri, 01 Aug 2025 00:00:00 GMT

You are given red and blue colored balls. You need to arrange them in rows to form a triangle where adjacent rows have different colors. Find the maximum height.

Smallest Absent Positive Greater Than Average

Fri, 01 Aug 2025 00:00:00 GMT

Find the smallest positive integer not present in the array that is strictly greater than the array's average.

Divisible and Non-divisible Sums Difference

Thu, 31 Jul 2025 00:00:00 GMT

Calculate the difference between the sum of numbers divisible by m and the sum of numbers not divisible by m in the range [1, n].

Divide a String Into Groups of Size k

Wed, 30 Jul 2025 00:00:00 GMT

Divide a string into groups of size k, filling the last group with a specific character if it is too short.

Stone Removal Game

Wed, 30 Jul 2025 00:00:00 GMT

Alice and Bob take turns removing stones — Alice starts with 10, then 9, 8, … decreasing each turn. The player who cannot remove the required stones loses.

Valid Phone Numbers

Tue, 29 Jul 2025 00:00:00 GMT

Given a text file, print all valid phone numbers that match specific formats.

Rotate String

Mon, 28 Jul 2025 00:00:00 GMT

Check if one string can become another by rotating characters.

Find the Width of Columns of a Grid

Sun, 27 Jul 2025 00:00:00 GMT

Find the maximum string length of integers in each column of a grid matrix.

Moving Average from Data Stream

Sun, 27 Jul 2025 00:00:00 GMT

Calculate the moving average of the last size integers in a data stream.

Reshape Data: Pivot

Fri, 25 Jul 2025 00:00:00 GMT

Transform a DataFrame from long to wide format by pivoting specified columns.

Determine Color of a Chessboard Square

Thu, 24 Jul 2025 00:00:00 GMT

Determine if a given chessboard square coordinate is white or black based on alternating color patterns.

Projection Area of 3D Shapes

Wed, 23 Jul 2025 00:00:00 GMT

Calculate the total projection area of 3D shapes on three orthogonal planes.

Count Number of Pairs With Absolute Difference K

Tue, 22 Jul 2025 00:00:00 GMT

Count pairs (i,j) where i

Adjacent Increasing Subarrays Detection I

Tue, 22 Jul 2025 00:00:00 GMT

Check if there are two adjacent strictly increasing subarrays of length k in the given array.

Array Prototype Last

Mon, 21 Jul 2025 00:00:00 GMT

Write code to enhance all arrays with a last() method that returns the last element or -1 if empty.

Smallest Divisible Digit Product I

Mon, 21 Jul 2025 00:00:00 GMT

Find the smallest positive integer with n digits whose digit product is divisible by k.

Minimum Number of Flips to Reverse Binary String

Sat, 19 Jul 2025 00:00:00 GMT

Find the minimum number of bit flips needed to make a binary string equal to its reverse.

Root Equals Sum of Children

Thu, 17 Jul 2025 00:00:00 GMT

Check if the root node's value equals the sum of its left and right child values in a binary tree.

Alternating Digit Sum

Thu, 17 Jul 2025 00:00:00 GMT

Calculate the alternating sum of digits in a positive integer, starting with addition for the leftmost digit.

Maximum Average Subarray I

Thu, 17 Jul 2025 00:00:00 GMT

Find a contiguous subarray of length k with the maximum average value in an integer array.

Number of Students Doing Homework at a Given Time

Wed, 16 Jul 2025 00:00:00 GMT

Given start and end times for students' homework, count how many are working at a specific query time.

Minimum Distance Between BST Nodes

Wed, 16 Jul 2025 00:00:00 GMT

Find the minimum absolute difference between values of any two nodes in a Binary Search Tree.

Maximum Odd Binary Number

Tue, 15 Jul 2025 00:00:00 GMT

You are given a binary string s. Rearrange the bits to form the maximum possible odd binary number.

Leaf-Similar Trees

Mon, 14 Jul 2025 00:00:00 GMT

Check if two binary trees have the same leaf value sequence when traversed from left to right.

Check If a Word Occurs As a Prefix of Any Word in a Sentence

Thu, 10 Jul 2025 00:00:00 GMT

Given a sentence and a search word, find if the search word is a prefix of any word in the sentence and return its 1-indexed position.

Percentage of Users Attended a Contest

Wed, 09 Jul 2025 00:00:00 GMT

Calculate the percentage of users who registered for each contest, rounded to two decimal places.

Points That Intersect With Cars

Wed, 09 Jul 2025 00:00:00 GMT

Given a list of integer intervals representing cars, calculate the total number of unique integer points covered by any car.

Word Pattern

Wed, 09 Jul 2025 00:00:00 GMT

Given a pattern and a string s, find if s follows the same pattern. Requires a bijection between pattern letters and words.

Missing Ranges

Tue, 08 Jul 2025 00:00:00 GMT

You are given an inclusive range [lower, upper] and a sorted unique integer array nums. Return the smallest sorted list of ranges that cover every missing number exactly.

Count the Digits That Divide a Number

Tue, 08 Jul 2025 00:00:00 GMT

Count the number of digits in a number that divide the number evenly.

Rising Temperature

Sun, 06 Jul 2025 00:00:00 GMT

Find all dates' Ids with higher temperature compared to its previous dates (yesterday).

Day of the Year

Sat, 05 Jul 2025 00:00:00 GMT

Calculate the day number of the year given a date string in YYYY-MM-DD format.

Richest Customer Wealth

Fri, 04 Jul 2025 00:00:00 GMT

You are given an array accounts where accounts[i][j] is the money the i-th customer has in the j-th bank. Return the wealth that the richest customer has.

To Lower Case

Mon, 30 Jun 2025 00:00:00 GMT

Given a string s, return the string after replacing every uppercase letter with the same lowercase letter.

Convert 1D Array Into 2D Array

Sat, 28 Jun 2025 00:00:00 GMT

You are given a 0-indexed 1-dimensional array of distinct integers. Convert it into a 2-dimensional array with m rows and n columns.

Maximum Number of Pairs in Array

Sat, 28 Jun 2025 00:00:00 GMT

Count pairs of equal numbers in an array and return the number of pairs formed and leftover elements.

Remove Outermost Parentheses

Fri, 27 Jun 2025 00:00:00 GMT

Remove the outermost parentheses from every primitive string in the decomposition of a valid parentheses string.

Print in Order

Thu, 26 Jun 2025 00:00:00 GMT

Synchronize three threads to print methods in order: first, second, third.

Mirror Distance of an Integer

Thu, 26 Jun 2025 00:00:00 GMT

Calculate the absolute difference between an integer and its mirror (digit-reversed) value.

Baseball Game

Wed, 25 Jun 2025 00:00:00 GMT

Calculate the sum of baseball scores based on operations like integer, '+', 'D', and 'C'.

Number of Recent Calls

Wed, 25 Jun 2025 00:00:00 GMT

Count the number of recent requests within a 3000ms time frame using a queue-based approach.

Kids With the Greatest Number of Candies

Sun, 22 Jun 2025 00:00:00 GMT

Determine if a kid can have the greatest number of candies after receiving extraCandies.

Determine if String Halves Are Alike

Sun, 22 Jun 2025 00:00:00 GMT

Check if two halves of a string have the same number of vowels by splitting and counting.

Shortest Word Distance

Sun, 22 Jun 2025 00:00:00 GMT

Given a list of words and two specific words, find the minimum distance between their indices in the list.

Merge Similar Items

Sat, 21 Jun 2025 00:00:00 GMT

Merge two lists of items by summing weights of items with the same value, then return sorted by value.

Form Smallest Number From Two Digit Arrays

Sat, 21 Jun 2025 00:00:00 GMT

Given two digit arrays, find the smallest number containing at least one digit from each array.

Last Visited Integers

Fri, 20 Jun 2025 00:00:00 GMT

Given an array of strings, process integers and 'prev' commands to return the last visited integers.

Alternating Groups I

Fri, 20 Jun 2025 00:00:00 GMT

Count the number of alternating groups of three colors in a circular array where the first and third colors are the same.

Binary Tree Tilt

Wed, 18 Jun 2025 00:00:00 GMT

Calculate the sum of every tree node's tilt, where tilt is the absolute difference between left and right subtree sums.

Find Common Characters

Tue, 17 Jun 2025 00:00:00 GMT

Given an array of strings, return a list of characters that appear in all strings, including duplicates.

Count Largest Group

Tue, 17 Jun 2025 00:00:00 GMT

Group numbers 1 to n by digit sum and count how many groups have the largest size.

Replace All Digits with Characters

Tue, 17 Jun 2025 00:00:00 GMT

Replace each digit in a string with the character shifted by that digit from the previous character.

License Key Formatting

Tue, 17 Jun 2025 00:00:00 GMT

Reformat a license key string so that groups are separated by dashes, each group has exactly k characters, and all letters are uppercase.

Check if Bitwise OR Has Trailing Zeros

Mon, 16 Jun 2025 00:00:00 GMT

Check if there exists a pair of elements in an array whose bitwise OR results in an even number.

Find the Degree of Each Vertex

Mon, 16 Jun 2025 00:00:00 GMT

Calculate the degree of every vertex in an undirected graph given its number of vertices and edge list.

Decode the Message

Sun, 15 Jun 2025 00:00:00 GMT

Decode a message using a substitution cipher derived from the first occurrence of each letter in a given key.

Number of Distinct Averages

Sun, 15 Jun 2025 00:00:00 GMT

Calculate the number of distinct averages obtained by repeatedly pairing the minimum and maximum numbers in an array.

Final Value of Variable After Performing Operations

Sat, 14 Jun 2025 00:00:00 GMT

Calculate the final value of a variable after performing increment and decrement operations.

Design Parking System

Thu, 12 Jun 2025 00:00:00 GMT

Design a parking system that manages parking slots for big, medium, and small cars, checking availability upon entry.

Count the Number of Special Characters I

Thu, 12 Jun 2025 00:00:00 GMT

You are given a string word. A character is special if it appears in both lowercase and uppercase forms in word. Return the number of special characters.

Ransom Note

Thu, 12 Jun 2025 00:00:00 GMT

Given two strings ransomNote and magazine, return true if ransomNote can be constructed using letters from magazine.

Find Indices of Stable Mountains

Mon, 09 Jun 2025 00:00:00 GMT

Return indices of mountains with height strictly greater than threshold, excluding the first mountain.

Student Attendance Record I

Sun, 08 Jun 2025 00:00:00 GMT

Check if a student's attendance record is rewardable based on absence count and consecutive late days.

Distance Between Bus Stops

Sat, 07 Jun 2025 00:00:00 GMT

Find the shortest distance between two bus stops on a circular route.

Minimum Right Shifts to Sort the Array

Fri, 06 Jun 2025 00:00:00 GMT

Find the minimum right shifts to sort a distinct array, or return -1 if impossible.

Coupon Code Validator

Fri, 06 Jun 2025 00:00:00 GMT

Validate a coupon code based on length, character set, digit presence, uniqueness, and sorting order.

Find the Sum of Encrypted Integers

Thu, 05 Jun 2025 00:00:00 GMT

Calculate the sum of integers where each digit is replaced by the maximum digit found in that integer.

Biggest Single Number

Thu, 05 Jun 2025 00:00:00 GMT

Find the largest number that appears exactly once in a table. If no such number exists, return null.

Sum of Digits in Base K

Wed, 04 Jun 2025 00:00:00 GMT

Given an integer n in base 10 and a base k, return the sum of digits of n after converting to base k.

K Items With the Maximum Sum

Mon, 02 Jun 2025 00:00:00 GMT

You are given three types of items with values 1, 0, and -1. Pick exactly k items to maximize the sum.

Remove Trailing Zeros From a String

Mon, 02 Jun 2025 00:00:00 GMT

Given a positive integer num represented as a string, return the string without any trailing zeros.

Compute Decimal Representation

Sun, 01 Jun 2025 00:00:00 GMT

Convert a fraction to its decimal string representation, handling repeating decimals with parentheses.

Number of Valid Clock Times

Sat, 31 May 2025 00:00:00 GMT

Count valid times by replacing '?' digits in a 24-hour clock format.

Take Gifts From the Richest Pile

Sat, 31 May 2025 00:00:00 GMT

You are given an array of piles and an integer k. Pick the largest pile k times, take the floor of its square root, and return the sum of remaining gifts.

Maximum Product Difference Between Two Pairs

Fri, 30 May 2025 00:00:00 GMT

Find the maximum product difference between two pairs (a, b) and (c, d) in an array.

Find Nearest Point That Has the Same X or Y Coordinate

Wed, 28 May 2025 00:00:00 GMT

Find the point in an array that shares an x or y coordinate with a target point and has the smallest Manhattan distance.

Check Balanced String

Mon, 26 May 2025 00:00:00 GMT

Determine if a numeric string is balanced by comparing the sum of digits in the first half with the sum of digits in the second half.

Decrypt String from Alphabet to Integer Mapping

Sun, 25 May 2025 00:00:00 GMT

Given an encrypted string where 1-9 map to a-i and 10#-26# map to j-z, decrypt it to the original string.

Fix Names in a Table

Sun, 25 May 2025 00:00:00 GMT

Write a solution to fix user names in a table so that only the first character is uppercase and the rest are lowercase.

Delete Characters to Make Fancy String

Sat, 24 May 2025 00:00:00 GMT

Delete minimum characters from a string so no three consecutive characters are equal.

Binary Watch

Sat, 24 May 2025 00:00:00 GMT

Given the number of LEDs turned on, return all possible times a binary watch could display.

Number Complement

Sat, 24 May 2025 00:00:00 GMT

Find the complement of an integer by flipping all bits in its binary representation.

Remove Duplicates from Sorted List

Fri, 23 May 2025 00:00:00 GMT

Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.

Check if the Sentence Is Pangram

Thu, 22 May 2025 00:00:00 GMT

Determine if a given sentence contains every letter of the English alphabet at least once.

Count Indices With Opposite Parity

Wed, 21 May 2025 00:00:00 GMT

Count the number of indices where the index and the value at that index have opposite parity.

How Many Numbers Are Smaller Than the Current Number

Tue, 20 May 2025 00:00:00 GMT

Given an array nums, for each element find the count of numbers smaller than it in the array.

Redistribute Characters to Make All Strings Equal

Mon, 19 May 2025 00:00:00 GMT

Determine if you can redistribute characters between strings to make all strings equal.

Build Array from Permutation

Mon, 19 May 2025 00:00:00 GMT

Given a zero-based permutation nums, build an array ans where ans[i] = nums[nums[i]] for every 0 <= i < nums.length.

Partition Array Into Three Parts With Equal Sum

Sun, 18 May 2025 00:00:00 GMT

Check if an array can be split into three contiguous parts with equal sums.

Check if All Characters Have Equal Number of Occurrences

Sat, 17 May 2025 00:00:00 GMT

Given a string s, determine if all characters appear the same number of times.

Average of Levels in Binary Tree

Sat, 17 May 2025 00:00:00 GMT

Given the root of a binary tree, return the average value of the nodes on each level in the form of an array.

Select Data

Fri, 16 May 2025 00:00:00 GMT

Select specific columns (name and age) from a DataFrame containing student information.

String Matching in an Array

Sun, 11 May 2025 00:00:00 GMT

Find all strings in an array that are substrings of another string in the same array.

Sum of Values at Indices With K Set Bits

Sun, 11 May 2025 00:00:00 GMT

Return the sum of all nums[i] where the index i has exactly k set bits in its binary representation.

Sum of Elements With Frequency Divisible by K

Sun, 11 May 2025 00:00:00 GMT

Given an array nums and integer k, return sum of elements whose frequency is divisible by k.

Invert Binary Tree

Sat, 10 May 2025 00:00:00 GMT

Given the root of a binary tree, invert the tree, and return its root.

Maximize Sum Of Array After K Negations

Fri, 09 May 2025 00:00:00 GMT

Given an integer array nums and an integer k, modify the array by choosing an index i and replacing nums[i] with -nums[i] exactly k times to maximize the sum of the array.

Count the Number of Consistent Strings

Thu, 08 May 2025 00:00:00 GMT

You are given a string allowed and an array of strings words. Return the number of strings in words that are consistent with allowed.

The Number of Employees Which Report to Each Employee

Thu, 08 May 2025 00:00:00 GMT

Count the number of employees that report to each employee and calculate their average age.

Concatenate Non-Zero Digits and Multiply by Sum I

Thu, 08 May 2025 00:00:00 GMT

Given an integer n, return the product of the sum of its non-zero digits and the integer formed by concatenating its non-zero digits.

Perfect Number

Thu, 08 May 2025 00:00:00 GMT

A perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself.

Binary Number with Alternating Bits

Thu, 08 May 2025 00:00:00 GMT

Check if a positive integer has alternating bits where no two adjacent bits are the same.

Path Sum

Wed, 07 May 2025 00:00:00 GMT

Given the root of a binary tree and an integer targetSum, return true if the tree has a root-to-leaf path where the sum of values equals targetSum.

Maximum 69 Number

Tue, 06 May 2025 00:00:00 GMT

Given a number consisting only of digits 6 and 9, return the maximum number by changing at most one digit (6 to 9 or 9 to 6).

Average Time of Process per Machine

Tue, 06 May 2025 00:00:00 GMT

Calculate the average time each machine takes to complete a process using start and end timestamps.

Average Value of Even Numbers That Are Divisible by Three

Tue, 06 May 2025 00:00:00 GMT

Calculate the average of numbers in an array that are divisible by both 2 and 3.

Unique Morse Code Words

Mon, 05 May 2025 00:00:00 GMT

International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes. Given a list of words, translate each word into Morse code and return the number of unique transformations.

Longest Strictly Increasing or Strictly Decreasing Subarray

Sun, 04 May 2025 00:00:00 GMT

Find the length of the longest subarray that is either strictly increasing or strictly decreasing.

Find the XOR of Numbers Which Appear Twice

Sun, 04 May 2025 00:00:00 GMT

You are given an integer array nums. Return the XOR of all the numbers that appear exactly twice in the array.

First Letter to Appear Twice

Wed, 30 Apr 2025 00:00:00 GMT

Find the first letter that appears twice in a string of lowercase English letters.

Number of Good Pairs

Tue, 29 Apr 2025 00:00:00 GMT

Count pairs of indices where nums[i] equals nums[j] and i is less than j.

Minimum Element After Replacement With Digit Sum

Tue, 29 Apr 2025 00:00:00 GMT

Replace each array element with the sum of its digits and find the minimum value.

Second Largest Digit in a String

Sun, 27 Apr 2025 00:00:00 GMT

Find the second largest unique digit in a string containing alphanumeric characters.

Crawler Log Folder

Sat, 26 Apr 2025 00:00:00 GMT

Calculate the minimum steps to return to the main folder from the current folder after performing a series of move operations.

Count Prefix and Suffix Pairs I

Fri, 25 Apr 2025 00:00:00 GMT

Count pairs of strings where the earlier string is both a prefix and a suffix of the later string.

Find the Town Judge

Mon, 21 Apr 2025 00:00:00 GMT

Identify the town judge who is trusted by everyone but trusts no one, given a list of trust relationships.

Relative Sort Array

Sun, 20 Apr 2025 00:00:00 GMT

Sort arr1 so elements follow the relative order of arr2, with remaining elements sorted ascending at the end.

Reverse Degree of a String

Sat, 19 Apr 2025 00:00:00 GMT

Calculate the sum of reverse degrees of characters in a string, where reverse degree is the index in the reversed string plus one.

Valid Elements in an Array

Sat, 19 Apr 2025 00:00:00 GMT

Count the number of elements in an array that are strictly greater than the sum of all elements to their left.

Base 7

Sat, 19 Apr 2025 00:00:00 GMT

Given an integer, return its base 7 representation as a string.

Interval Cancellation

Fri, 18 Apr 2025 00:00:00 GMT

Implement a function to schedule a recurring function call with an initial delay and return a function to cancel it.

Unique 3-Digit Even Numbers

Fri, 18 Apr 2025 00:00:00 GMT

Given an array of digits, return the count of unique 3-digit even numbers that can be formed where each digit is used at most once.

Last Stone Weight

Thu, 17 Apr 2025 00:00:00 GMT

We have a collection of stones, each stone has a positive integer weight. Each turn, we choose the two heaviest stones and smash them together.

Minimum Value to Get Positive Step by Step Sum

Sun, 13 Apr 2025 00:00:00 GMT

Find the minimum positive start value so that the running sum never drops below 1.

Sum of Good Numbers

Fri, 11 Apr 2025 00:00:00 GMT

Given an array of integers, return the sum of numbers that are divisible by their digit count.

Number of Lines To Write String

Fri, 11 Apr 2025 00:00:00 GMT

Calculate the number of lines and width of the last line when writing a string with given character widths.

Duplicate Emails

Mon, 07 Apr 2025 00:00:00 GMT

Write a SQL query to find all duplicate emails in a table named Person.

Binary Tree Preorder Traversal

Fri, 04 Apr 2025 00:00:00 GMT

Return the preorder traversal of a binary tree's node values.

Reverse Prefix of Word

Fri, 04 Apr 2025 00:00:00 GMT

Given a word and a character, reverse the segment of the word starting from index 0 to the first occurrence of the character.

Range Sum of BST

Fri, 04 Apr 2025 00:00:00 GMT

Given the root node of a binary search tree and two integers low and high, return the sum of values of all nodes with a value in the inclusive range [low, high].

Count Pairs That Form a Complete Day I

Wed, 02 Apr 2025 00:00:00 GMT

Count pairs of indices where the sum of hours is divisible by 24.

Element Appearing More Than 25% In Sorted Array

Tue, 01 Apr 2025 00:00:00 GMT

Given a sorted integer array, find the element that appears more than 25% of the time.

Divide Array Into Equal Pairs

Mon, 31 Mar 2025 00:00:00 GMT

Determine if an array can be split into pairs of equal numbers by checking if every element occurs an even number of times.

Triangle Judgement

Mon, 31 Mar 2025 00:00:00 GMT

Determine if three given side lengths can form a valid triangle for each row in the table.

Find Words That Can Be Formed by Characters

Sun, 30 Mar 2025 00:00:00 GMT

You are given an array of strings words and a string chars. Return the sum of lengths of all strings in words that can be formed using characters from chars.

Combine Two Tables

Sun, 30 Mar 2025 00:00:00 GMT

Write a SQL query to report the first name, last name, city, and state of each person in the Person table.

Calculate Digit Sum of a String

Sun, 30 Mar 2025 00:00:00 GMT

You are given a string s consisting of digits and an integer k. Perform digit sum grouping operations until the string length is <= k.

Split With Minimum Sum

Sat, 29 Mar 2025 00:00:00 GMT

Given a positive integer num, split its digits into two new integers to minimize their sum.

Find Closest Person

Wed, 26 Mar 2025 00:00:00 GMT

Given an array of positions and your position, find the minimum distance to any person.

Find Minimum Log Transportation Cost

Wed, 26 Mar 2025 00:00:00 GMT

Calculate the minimum cost to transport logs given a truck capacity, where cost is the max weight per trip.

First Unique Character in a String

Wed, 26 Mar 2025 00:00:00 GMT

Find the first non-repeating character in a string and return its index, or -1 if none exists.

Article Views I

Mon, 24 Mar 2025 00:00:00 GMT

Find all authors who viewed their own articles at least once, sorted by author_id.

Find the Number of Winning Players

Sun, 23 Mar 2025 00:00:00 GMT

Determine the number of players who have picked at least x balls of the same color, where x is the player's ID.

Project Employees I

Sat, 22 Mar 2025 00:00:00 GMT

Report the average experience years of employees for each project, rounded to two decimal places.

Prime Arrangements

Fri, 21 Mar 2025 00:00:00 GMT

Return the number of permutations of 1 to n where prime numbers are at prime indices, modulo 10⁹ + 7.

Isomorphic Strings

Thu, 20 Mar 2025 00:00:00 GMT

Check if two strings are isomorphic by replacing characters in one string to form the other.

Number of Students Unable to Eat Lunch

Tue, 18 Mar 2025 00:00:00 GMT

Students queue up for sandwiches. If the top sandwich doesn't match a student's preference, they move to the back. Count students who never eat.

Most Frequent Even Element

Mon, 17 Mar 2025 00:00:00 GMT

Find the most frequent even element in an array. If multiple have same frequency, return smallest. Return -1 if no even elements.

Smallest Even Multiple

Mon, 17 Mar 2025 00:00:00 GMT

Find the smallest positive multiple of n that is also even.

Find Subsequence of Length K With the Largest Sum

Thu, 13 Mar 2025 00:00:00 GMT

Find a subsequence of length k with maximum sum from an array, maintaining original order.

Check if a String Is an Acronym of Words

Wed, 12 Mar 2025 00:00:00 GMT

Determine if a given string is formed by the first letters of an array of words.

Minimum Number of Chairs in a Waiting Room

Wed, 12 Mar 2025 00:00:00 GMT

Find the minimum number of chairs needed in a waiting room given a string of people entering ('E') and leaving ('L').

Min Cost Climbing Stairs

Sun, 09 Mar 2025 00:00:00 GMT

Find the minimum cost to reach the top of the floor, where you can start from step 0 or 1 and climb 1 or 2 steps.

Snake in Matrix

Sat, 08 Mar 2025 00:00:00 GMT

Simulate a snake moving in an n x n matrix based on a list of directional commands and return its final position.

Third Maximum Number

Sat, 08 Mar 2025 00:00:00 GMT

Given an integer array, return the third distinct maximum number, or the maximum if it doesn't exist.

Product Sales Analysis I

Thu, 06 Mar 2025 00:00:00 GMT

Report product_id, year, and quantity for each sale from the Sales table.

Check if Strings Can be Made Equal With Operations I

Thu, 06 Mar 2025 00:00:00 GMT

Determine if two strings can be made equal by swapping characters at indices with the same parity.

Count Items Matching a Rule

Sun, 02 Mar 2025 00:00:00 GMT

Count items in a list that match a given rule based on type, color, or name attributes.

Flood Fill

Sun, 02 Mar 2025 00:00:00 GMT

Change the color of a connected region in an image starting from a given pixel using flood fill algorithm.

Minimum Hours of Training to Win a Competition

Sat, 01 Mar 2025 00:00:00 GMT

Calculate minimum training hours needed to win all competitions by tracking energy and experience deficits.

Minimum Operations to Make Array Sum Divisible by K

Sat, 01 Mar 2025 00:00:00 GMT

Find the minimum number of elements to remove from an array so that the sum of the remaining elements is divisible by k.

Sum of Digits of String After Convert

Thu, 27 Feb 2025 00:00:00 GMT

Convert string to integer string, then repeatedly sum digits k times.

Return Length of Arguments Passed

Thu, 27 Feb 2025 00:00:00 GMT

Write a function that returns the number of arguments passed to it.

Get Maximum in Generated Array

Wed, 26 Feb 2025 00:00:00 GMT

Generate an array based on specific index rules and find the maximum value within it.

Maximum Length Substring With Two Occurrences

Tue, 25 Feb 2025 00:00:00 GMT

Find the longest substring where no character appears more than twice.

Intersection of Two Arrays

Sun, 23 Feb 2025 00:00:00 GMT

Given two integer arrays, return an array of their intersection. Each element in the result must be unique.

Minimum Distance Between Three Equal Elements I

Fri, 21 Feb 2025 00:00:00 GMT

Find the minimum distance between three equal elements in an array.

Rectangle Overlap

Fri, 21 Feb 2025 00:00:00 GMT

Determine if two axis-aligned rectangles overlap by checking their projections on the x and y axes.

Longest Continuous Increasing Subsequence

Wed, 19 Feb 2025 00:00:00 GMT

Find the length of the longest continuous increasing subsequence (subarray) in an unsorted array.

Two Sum Less Than K

Tue, 18 Feb 2025 00:00:00 GMT

Given an array nums and an integer k, find the maximum sum of two numbers less than k.

Classes With at Least 5 Students

Mon, 17 Feb 2025 00:00:00 GMT

Find all classes that have at least 5 students enrolled.

User Activity for the Past 30 Days I

Sun, 16 Feb 2025 00:00:00 GMT

Find the daily active user count for a period of 30 days ending on 2019-07-27 inclusive.

Count Days Spent Together

Sun, 16 Feb 2025 00:00:00 GMT

Alice and Bob are traveling to Rome for vacation. Calculate the number of days they spend together based on their arrival and departure dates.

Binary Gap

Sat, 15 Feb 2025 00:00:00 GMT

Given a positive integer n, find the maximum distance between two consecutive 1's in its binary representation.

Distribute Candies to People

Fri, 14 Feb 2025 00:00:00 GMT

We distribute candies to people in turns, giving 1, 2, 3... candies sequentially. Return the final array of candies each person holds.

Largest Local Values in a Matrix

Fri, 14 Feb 2025 00:00:00 GMT

You are given an n x n integer matrix grid. Generate an (n-2) x (n-2) matrix maxLocal where each element is the largest value in the contiguous 3x3 submatrix of grid.

N-th Tribonacci Number

Wed, 12 Feb 2025 00:00:00 GMT

Calculate the n-th Tribonacci number, defined by the recurrence relation Tn = Tn-1 + Tn-2 + Tn-3.

Sleep

Wed, 12 Feb 2025 00:00:00 GMT

Implement an async sleep function that delays execution for a specified number of milliseconds.

Find N Unique Integers Sum up to Zero

Mon, 10 Feb 2025 00:00:00 GMT

Given an integer n, return any array of n unique integers that sum up to zero.

Find Lucky Integer in an Array

Mon, 10 Feb 2025 00:00:00 GMT

Given an array of integers, a lucky integer is an integer which has a frequency in the array equal to its value. Return the largest lucky integer, or -1 if none exists.

Find Users With Valid E-Mails

Mon, 10 Feb 2025 00:00:00 GMT

Find users with valid e-mails where prefix starts with a letter and domain is @leetcode.com

Maximum Product of Three Numbers

Mon, 10 Feb 2025 00:00:00 GMT

Given an integer array nums, find three numbers whose product is maximum and return the maximum product.

Total Distance Traveled

Sun, 09 Feb 2025 00:00:00 GMT

Calculate the total distance a truck can travel given a main and auxiliary fuel tank with specific transfer rules.

DI String Match

Sat, 08 Feb 2025 00:00:00 GMT

Given a string of I and D characters, reconstruct a permutation where I means increase and D means decrease.

Binary Prefix Divisible By 5

Fri, 07 Feb 2025 00:00:00 GMT

Given a binary array, determine if the number formed by each prefix is divisible by 5.

Employee Bonus

Wed, 05 Feb 2025 00:00:00 GMT

Select all employees with a bonus less than 1000, returning their name and bonus amount.

Find the Child Who Has the Ball After K Seconds

Mon, 03 Feb 2025 00:00:00 GMT

You are given n children standing in a line. The ball starts at child 0 and moves back and forth. Return the child holding the ball after k seconds.

Sum of All Subset XOR Totals

Sun, 02 Feb 2025 00:00:00 GMT

Calculate the sum of XOR totals for every subset of an array.

Maximum Units on a Truck

Fri, 31 Jan 2025 00:00:00 GMT

Maximize the total number of units loaded on a truck by selecting boxes with the highest number of units per box first.

Find the Winning Player in Coin Game

Wed, 29 Jan 2025 00:00:00 GMT

Determine the winner of a coin game where Alice and Bob remove 2, 3, or 5 coins from their own piles.

Count Elements With Strictly Smaller and Greater Elements

Tue, 28 Jan 2025 00:00:00 GMT

Count elements in an array that have both a strictly smaller and a strictly greater element present.

Cells in a Range on an Excel Sheet

Tue, 28 Jan 2025 00:00:00 GMT

Return all cells in the inclusive range of an Excel sheet given a string like 'K1:L2'.

Function Composition

Mon, 27 Jan 2025 00:00:00 GMT

Given an array of functions, return a new function that represents the composition of all functions.

Faulty Keyboard

Mon, 27 Jan 2025 00:00:00 GMT

Your laptop keyboard is faulty: typing 'i' reverses the string typed so far. Return the final string displayed.

Create a DataFrame from List

Sat, 25 Jan 2025 00:00:00 GMT

Create a pandas DataFrame from a given 2D list with specified column names.

The Latest Login in 2020

Fri, 24 Jan 2025 00:00:00 GMT

Find the latest login timestamp for each user in the year 2020 from the Logins table.

Number of Arithmetic Triplets

Wed, 22 Jan 2025 00:00:00 GMT

Count the number of index triplets (i, j, k) in a strictly increasing array where the differences between consecutive elements equal a given value.

Number of Unique Subjects Taught by Each Teacher

Tue, 21 Jan 2025 00:00:00 GMT

Count the number of unique subjects each teacher teaches from the Teacher table.

Absolute Difference Between Maximum and Minimum K Elements

Tue, 21 Jan 2025 00:00:00 GMT

Find the minimum possible absolute difference between the maximum and minimum elements of any subset of size k from the array.

Largest Positive Integer That Exists With Its Negative

Mon, 20 Jan 2025 00:00:00 GMT

Given an integer array nums, return the largest positive integer k such that -k also exists in the array. If there is no such integer, return -1.

Reverse String

Mon, 20 Jan 2025 00:00:00 GMT

Write a function that reverses a string. The input string is given as an array of characters s. You must do this by modifying the input array in-place with O(1) extra memory.

Jewels and Stones

Sun, 19 Jan 2025 00:00:00 GMT

You're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have. Return the number of stones that are also jewels.

Generate Fibonacci Sequence

Sat, 18 Jan 2025 00:00:00 GMT

Write a generator function that yields Fibonacci numbers starting from 0, 1.

Split Strings by Separator

Fri, 17 Jan 2025 00:00:00 GMT

Given an array of strings and a separator character, split each string by the separator and return a 2D array of non-empty substrings.

Method Chaining

Thu, 16 Jan 2025 00:00:00 GMT

Implement a class with methods that can be chained together to perform operations.

Rearrange Spaces Between Words

Wed, 15 Jan 2025 00:00:00 GMT

Rearrange spaces between words to distribute them equally, placing extra spaces at the end.

Determine if Two Events Have Conflict

Mon, 13 Jan 2025 00:00:00 GMT

Given two time intervals, check if they overlap or touch at the boundaries.

Minimum Difference Between Highest and Lowest of K Scores

Tue, 07 Jan 2025 00:00:00 GMT

Find the minimum possible difference between the highest and lowest of k scores from an array.

Most Common Word

Tue, 07 Jan 2025 00:00:00 GMT

Find the most frequent word in a paragraph that is not in the banned list.

Maximum Ascending Subarray Sum

Mon, 06 Jan 2025 00:00:00 GMT

Find the maximum sum of an ascending subarray where each element is strictly greater than the previous element.

Zigzag Grid Traversal With Skip

Mon, 06 Jan 2025 00:00:00 GMT

Traverse a 2D grid in a zigzag pattern, skipping specific elements, and return the result in a 1D array.

Intersection of Two Arrays II

Mon, 06 Jan 2025 00:00:00 GMT

Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must appear as many times as it shows in both arrays.

Number of Segments in a String

Sun, 05 Jan 2025 00:00:00 GMT

Count the number of segments in a string, where a segment is defined as a contiguous sequence of non-space characters.

Reverse String II

Thu, 02 Jan 2025 00:00:00 GMT

Given a string s and an integer k, reverse the first k characters for every 2k characters.

Valid Mountain Array

Wed, 01 Jan 2025 00:00:00 GMT

Check if an array strictly increases then strictly decreases.

Convert Binary Number in a Linked List to Integer

Tue, 31 Dec 2024 00:00:00 GMT

Given head which is a reference node to a singly-linked list, return the decimal value of the binary number represented by the linked list.

Big Countries

Mon, 30 Dec 2024 00:00:00 GMT

Find the name, population, and area of countries with an area of at least three million square kilometers or a population of at least twenty-five million.

Matrix Similarity After Cyclic Shifts

Sun, 29 Dec 2024 00:00:00 GMT

Check if a matrix remains identical after applying k cyclic shifts (right for even rows, left for odd rows).

Defuse the Bomb

Sat, 28 Dec 2024 00:00:00 GMT

Decrypt the circular array code by summing the next k elements or previous k elements based on the value of k.

Shuffle String

Thu, 26 Dec 2024 00:00:00 GMT

Given a string s and an integer array indices, shuffle the string so that the character at the ith position moves to indices[i] in the shuffled string.

Distribute Money to Maximum Children

Wed, 25 Dec 2024 00:00:00 GMT

Distribute money to children such that no child gets 4 dollars and the number of children getting 8 dollars is maximized.

Number of Changing Keys

Wed, 25 Dec 2024 00:00:00 GMT

Count the number of times you need to change keys while typing a string, considering case changes.

Thousand Separator

Tue, 24 Dec 2024 00:00:00 GMT

Given an integer n, add a dot (.) as the thousands separator and return it in string format.

Number of Bit Changes to Make Two Integers Equal

Sun, 22 Dec 2024 00:00:00 GMT

Find minimum bit changes to make n equal to k by only changing 0s to 1s.

Distribute Candies Among Children I

Sat, 21 Dec 2024 00:00:00 GMT

Count ways to distribute n candies among 3 children with each getting 1 to limit candies.

Count Good Triplets

Thu, 19 Dec 2024 00:00:00 GMT

Count the number of triplets (i, j, k) such that the absolute differences between elements satisfy given conditions.

Maximum Product of Two Digits

Mon, 16 Dec 2024 00:00:00 GMT

Find the maximum product of any two digits from a given integer.

Find the Key of the Numbers

Sat, 14 Dec 2024 00:00:00 GMT

You are given three integers. Find the key by taking the maximum digit at each place value among the three numbers.

Find X-Sum of All K-Long Subarrays I

Fri, 13 Dec 2024 00:00:00 GMT

Calculate the x-sum for every subarray of length k, where x-sum is the sum of top x most frequent elements.

Find All K-Distant Indices in an Array

Thu, 12 Dec 2024 00:00:00 GMT

Find all indices i in an array such that there exists an index j where nums[j] equals key and the absolute difference between i and j is at most k.

Find the Largest Almost Missing Integer

Thu, 12 Dec 2024 00:00:00 GMT

Find the largest integer x not in nums such that x+1 is in nums.

Consecutive Characters

Tue, 10 Dec 2024 00:00:00 GMT

Given a string s, find the maximum length of a substring containing only one unique character.

Find Maximum Number of String Pairs

Mon, 09 Dec 2024 00:00:00 GMT

You are given a 0-indexed array words consisting of distinct strings. Return the maximum number of pairs (i, j) such that i < j and words[i] is equal to the reversed string of words[j].

Maximum Population Year

Sat, 07 Dec 2024 00:00:00 GMT

Find the year with the highest population based on birth and death years.

Count Vowel Substrings of a String

Fri, 06 Dec 2024 00:00:00 GMT

Count the number of substrings that contain only vowels and include all five vowels at least once.

Guess Number Higher or Lower

Thu, 05 Dec 2024 00:00:00 GMT

We are playing the Guess Game. I pick a number from 1 to n. You have to guess which number I picked using the guess API.

Count Operations to Obtain Zero

Wed, 04 Dec 2024 00:00:00 GMT

Calculate the number of operations to reduce two numbers to zero by repeatedly subtracting the smaller from the larger.

Minimum Absolute Difference in BST

Mon, 02 Dec 2024 00:00:00 GMT

Find the minimum absolute difference between values of any two nodes in a Binary Search Tree.

Actors and Directors Who Cooperated At Least Three Times

Mon, 25 Nov 2024 00:00:00 GMT

Find pairs of actors and directors who have worked together at least three times using SQL aggregation.

Replace Elements with Greatest Element on Right Side

Mon, 25 Nov 2024 00:00:00 GMT

Replace each element in an array with the greatest element to its right, and the last element with -1.

AWARDS

Mon, 25 Nov 2024 00:00:00 GMT

The **Awards Platform** is a modern web application designed to simplify the process of creating, managing, and showcasing awards. Tailored for organizations, teams, and events, it combines a sleek user interface with a powerful backend, making nominations, voting, and winner announcements effortless. Built with **TailwindCSS**, it ensures a visually stunning and fully responsive design for all devices.

Maximum Product of Two Elements in an Array

Sat, 23 Nov 2024 00:00:00 GMT

Find the maximum value of (nums[i]-1)*(nums[j]-1) by choosing two different indices i and j from the array.

Minimum Positive Sum Subarray

Sat, 23 Nov 2024 00:00:00 GMT

Find the smallest sum of any non-empty subarray that is strictly positive.

Minimum Subsequence in Non-Increasing Order

Thu, 21 Nov 2024 00:00:00 GMT

Find the minimum size subsequence where the sum of its elements is strictly greater than the sum of the remaining elements.

Smallest Number With All Set Bits

Thu, 21 Nov 2024 00:00:00 GMT

Find the smallest number with all bits set for a given number of bits n.

Binary Tree Paths

Wed, 20 Nov 2024 00:00:00 GMT

Given the root of a binary tree, return all root-to-leaf paths in any order.

The Two Sneaky Numbers of Digitville

Wed, 20 Nov 2024 00:00:00 GMT

Find the two numbers that appear twice in an array where all other numbers appear exactly once.

Duplicate Zeros

Sat, 16 Nov 2024 00:00:00 GMT

Duplicate each occurrence of zero in a fixed-length array, shifting remaining elements to the right.

Reformat The String

Sat, 16 Nov 2024 00:00:00 GMT

You are given an alphanumeric string s. Reformat the string so that no two adjacent characters are the same type (letter vs digit). Return the reformatted string or empty if impossible.

Traffic Signal Color

Sat, 16 Nov 2024 00:00:00 GMT

Determine the color of a traffic signal after a given time, knowing it cycles Green -> Yellow -> Red -> Green every second.

Sum of Squares of Special Elements

Thu, 14 Nov 2024 00:00:00 GMT

Calculate the sum of squares of elements whose 1-indexed positions divide the array length.

Find the Array Concatenation Value

Tue, 12 Nov 2024 00:00:00 GMT

Calculate the total value by repeatedly concatenating the first and last elements of an array until it is empty.

Find Smallest Letter Greater Than Target

Tue, 12 Nov 2024 00:00:00 GMT

Given a sorted characters array and a target character, find the smallest character in the array that is larger than the target.

Minimum Absolute Difference

Sun, 10 Nov 2024 00:00:00 GMT

Given an array of distinct integers, find all pairs of elements with the minimum absolute difference.

Sum of Variable Length Subarrays

Sat, 09 Nov 2024 00:00:00 GMT

Calculate the total sum of subarrays defined by a corresponding lengths array.

Distribute Candies

Fri, 08 Nov 2024 00:00:00 GMT

Alice has n candies of different types. She must eat n/2 of them. Return the maximum number of different types she can eat.

Decode XORed Array

Thu, 07 Nov 2024 00:00:00 GMT

Given an encoded array and the first element of the original array, reconstruct the original array using XOR properties.

Check If N and Its Double Exist

Sat, 02 Nov 2024 00:00:00 GMT

Given an array of integers, return true if there exist indices i and j such that i != j and arr[i] == 2 * arr[j].

Largest Number At Least Twice of Others

Fri, 01 Nov 2024 00:00:00 GMT

Find the index of the largest integer if it is at least twice as much as every other number in the array.

Sort Even and Odd Indices Independently

Thu, 31 Oct 2024 00:00:00 GMT

Sort values at even indices in non-decreasing order and odd indices in non-increasing order.

Apple Redistribution into Boxes

Wed, 30 Oct 2024 00:00:00 GMT

Determine the minimum number of boxes needed to redistribute all apples, given the weight of apples and the capacity of boxes.

Categorize Box According to Criteria

Tue, 29 Oct 2024 00:00:00 GMT

Determine if a box is Bulky, Heavy, Both, or Neither based on its dimensions and mass.

Count the Number of Vowel Strings in Range

Mon, 28 Oct 2024 00:00:00 GMT

You are given a 0-indexed string array words and two integers left and right. Return the number of vowel strings in the range [left, right].

Reshape Data: Concatenate

Mon, 28 Oct 2024 00:00:00 GMT

Concatenate two DataFrames into a single DataFrame using Pandas.

First Bad Version

Sun, 27 Oct 2024 00:00:00 GMT

Find the first bad version using binary search given an API to check if a version is bad.

Truncate Sentence

Sat, 26 Oct 2024 00:00:00 GMT

Return the first k words of a sentence separated by spaces.

Kth Distinct String in an Array

Sat, 26 Oct 2024 00:00:00 GMT

Find the kth distinct string in an array, where a distinct string appears exactly once.

Intersection of Multiple Arrays

Sat, 26 Oct 2024 00:00:00 GMT

Find the intersection of multiple arrays containing distinct integers.

Circular Sentence

Sat, 26 Oct 2024 00:00:00 GMT

Check if a sentence is circular by verifying that the last character of each word matches the first character of the next word, including the circular wrap-around.

Queries Quality and Percentage

Fri, 25 Oct 2024 00:00:00 GMT

Calculate query quality and percentage from a queries table containing query_name, result, position, and rating.

Number Of Rectangles That Can Form The Largest Square

Mon, 21 Oct 2024 00:00:00 GMT

Given rectangles, find how many can form the largest possible square by cutting.

Fizz Buzz

Mon, 21 Oct 2024 00:00:00 GMT

Given an integer n, return a string array answer (1-indexed) where answer[i] is 'FizzBuzz' if i is divisible by 3 and 5, 'Fizz' if divisible by 3, 'Buzz' if divisible by 5, or str(i) otherwise.

Pascal's Triangle II

Sat, 19 Oct 2024 00:00:00 GMT

Return the kth index row of Pascal's triangle where each number is the sum of the two numbers directly above it.

Minimum Cost to Reach Every Position

Fri, 18 Oct 2024 00:00:00 GMT

Calculate the minimum cost to reach each index in an array where you can jump 1 or 2 steps.

Is Object Empty

Thu, 17 Oct 2024 00:00:00 GMT

Given an object or an array, return true if it is empty, otherwise return false.

Minimum Sum of Four Digit Number After Splitting Digits

Wed, 16 Oct 2024 00:00:00 GMT

Split a four-digit number into two new numbers using all digits to minimize their sum.

Subarrays Distinct Element Sum of Squares I

Wed, 16 Oct 2024 00:00:00 GMT

Calculate the sum of squares of distinct element counts for all subarrays of the given array.

Minimum Operations to Make the Array Increasing

Mon, 14 Oct 2024 00:00:00 GMT

Return the minimum number of operations to make an array strictly increasing by incrementing elements.

Counting Words With a Given Prefix

Mon, 14 Oct 2024 00:00:00 GMT

Return the number of strings in an array that start with a given prefix.

Implement Queue using Stacks

Mon, 14 Oct 2024 00:00:00 GMT

Implement a FIFO queue using only two stacks with push, pop, peek, and empty operations.

Change Data Type

Mon, 14 Oct 2024 00:00:00 GMT

Convert a value from one data type to another, handling edge cases.

Earliest Finish Time for Land and Water Rides I

Mon, 14 Oct 2024 00:00:00 GMT

Find the minimum total time to complete one land ride and one water ride, where the land ride must be taken first.

Find All Numbers Disappeared in an Array

Mon, 14 Oct 2024 00:00:00 GMT

Given an array of n integers where 1 ≤ nums[i] ≤ n, find all integers in [1, n] that do not appear in the array.

Evaluate Boolean Binary Tree

Sun, 13 Oct 2024 00:00:00 GMT

Evaluate boolean expression represented by a binary tree where leaves are 0/1 and internal nodes are OR/AND operations.

Toeplitz Matrix

Sat, 12 Oct 2024 00:00:00 GMT

Given a matrix, return true if it is a Toeplitz matrix where every diagonal has the same elements.

Maximum Unique Subarray Sum After Deletion

Tue, 08 Oct 2024 00:00:00 GMT

Find the maximum sum of a subarray with all unique elements after deleting at most one element from the array.

Sort Integers by Binary Reflection

Mon, 07 Oct 2024 00:00:00 GMT

Sort an array of integers based on the value of their binary reflection (reversed bits).

Transform Array by Parity

Fri, 04 Oct 2024 00:00:00 GMT

Rearrange array so all even numbers come before odd numbers while maintaining relative order.

Remove One Element to Make the Array Strictly Increasing

Wed, 02 Oct 2024 00:00:00 GMT

Given an array, return true if it can be made strictly increasing by removing at most one element.

Maximum Count of Positive Integer and Negative Integer

Mon, 30 Sep 2024 00:00:00 GMT

Given a sorted array, return the maximum count between positive integers and negative integers. Zero is neither.

Shortest Subarray With OR at Least K I

Sat, 28 Sep 2024 00:00:00 GMT

Find the length of the shortest non-empty subarray where the bitwise OR of its elements is at least k.

Goal Parser Interpretation

Thu, 26 Sep 2024 00:00:00 GMT

Interpret the command string by mapping 'G' to 'G', '()' to 'o', and '(al)' to 'al'.

Reshape Data: Melt

Thu, 26 Sep 2024 00:00:00 GMT

Transform a wide-format DataFrame into a long-format DataFrame by unpivoting subject columns into rows.

Check if Two Chessboard Squares Have the Same Color

Thu, 26 Sep 2024 00:00:00 GMT

Determine if two given chessboard squares have the same color based on their coordinates.

Add Two Integers

Sun, 22 Sep 2024 00:00:00 GMT

Given two integers num1 and num2, return the sum of the two integers.

Day of the Week

Fri, 20 Sep 2024 00:00:00 GMT

Given a date, return the corresponding day of the week.

Minimum Operations to Make Array Values Equal to K

Thu, 19 Sep 2024 00:00:00 GMT

You are given an array nums and an integer k. In one operation, you can remove any element from nums that is greater than k. Return the minimum number of operations to make all elements in nums equal to k.

Find Closest Number to Zero

Wed, 18 Sep 2024 00:00:00 GMT

Given an integer array nums, find the number with the value closest to 0. If there is a tie, return the positive number.

Convert the Temperature

Wed, 18 Sep 2024 00:00:00 GMT

Convert Celsius to Kelvin and Fahrenheit using simple mathematical formulas.

Minimum Number of Moves to Seat Everyone

Tue, 17 Sep 2024 00:00:00 GMT

Match students to seats to minimize total moves by sorting both arrays and pairing corresponding elements.

Learning Management System (LMS)

Sun, 15 Sep 2024 00:00:00 GMT

A comprehensive Learning Management System built with JavaScript, React, and Tailwind CSS, featuring course management, video processing, and integration with Stripe and other services.

Swap Sex of Employees

Fri, 13 Sep 2024 00:00:00 GMT

Update all 'f' values to 'm' and all 'm' values to 'f' in the sex column of the Employee table.

Sort Integers by The Number of 1 Bits

Thu, 12 Sep 2024 00:00:00 GMT

Sort an array of integers based on the number of 1 bits in their binary representation. If counts are equal, sort by decimal value.

Largest Substring Between Two Equal Characters

Tue, 10 Sep 2024 00:00:00 GMT

Given a string s, find the maximum length of a substring between two equal characters.

Find the Highest Altitude

Tue, 10 Sep 2024 00:00:00 GMT

A biker starts at altitude 0 and travels through points with net altitude gains. Find the highest altitude reached during the trip.

Chunk Array

Tue, 10 Sep 2024 00:00:00 GMT

Split an array into chunks of a given size, with the last chunk potentially containing fewer elements.

Defanging an IP Address

Sat, 07 Sep 2024 00:00:00 GMT

Given a valid IP address, replace every '.' with '[.]' to defang it.

Valid Palindrome

Thu, 05 Sep 2024 00:00:00 GMT

Check if a string is a palindrome considering only alphanumeric characters and ignoring case.

Odd String Difference

Thu, 05 Sep 2024 00:00:00 GMT

Find the string with a unique difference pattern among an array of equal-length strings.

Maximum Number of Words Found in Sentences

Tue, 03 Sep 2024 00:00:00 GMT

Find the sentence with the most words by counting spaces in each string.

Latest Time You Can Obtain After Replacing Characters

Sun, 01 Sep 2024 00:00:00 GMT

Given a time string with '?' characters, replace them to form the latest valid time.

1-bit and 2-bit Characters

Sat, 31 Aug 2024 00:00:00 GMT

Determine if the last character in a binary array must be a 1-bit character, where 0 is 1-bit and 10/11 are 2-bit.

Check Divisibility by Digit Sum and Product

Wed, 28 Aug 2024 00:00:00 GMT

Determine if an integer is divisible by both the sum and the product of its digits.

List the Products Ordered in a Period

Mon, 26 Aug 2024 00:00:00 GMT

Write a solution to list the names and categories of products ordered in February 2020.

Univalued Binary Tree

Fri, 23 Aug 2024 00:00:00 GMT

Check if all nodes in a binary tree have the same value.

Average Salary Excluding the Minimum and Maximum Salary

Mon, 19 Aug 2024 00:00:00 GMT

Calculate the average salary excluding the minimum and maximum salary from an array.

Surface Area of 3D Shapes

Mon, 19 Aug 2024 00:00:00 GMT

Calculate the total surface area of a 3D shape represented by an n x n grid of cube heights.

Not Boring Movies

Fri, 16 Aug 2024 00:00:00 GMT

Find movies with odd ID and non-boring description, ordered by rating descending.

Subtract the Product and Sum of Digits of an Integer

Tue, 13 Aug 2024 00:00:00 GMT

Given an integer n, return the difference between the product of its digits and the sum of its digits.

Find the Difference of Two Arrays

Tue, 13 Aug 2024 00:00:00 GMT

Given two integer arrays, return distinct integers present in one but not the other.

Check If All 1's Are at Least Length K Places Away

Fri, 09 Aug 2024 00:00:00 GMT

Given an array of 0s and 1s, determine if every pair of adjacent 1s is separated by at least k 0s.

Check if Array Is Sorted and Rotated

Fri, 09 Aug 2024 00:00:00 GMT

Given an array nums, return true if the array was originally sorted in non-decreasing order and then rotated some number of positions.

Maximum Score After Splitting a String

Tue, 06 Aug 2024 00:00:00 GMT

Given a binary string, split it into left and right substrings to maximize the score of zeros in left plus ones in right.

Subtree of Another Tree

Tue, 06 Aug 2024 00:00:00 GMT

Given two binary trees, check if one tree is a subtree of the other by comparing structure and node values.

Divisor Game

Fri, 02 Aug 2024 00:00:00 GMT

Alice and Bob play a game with a number n. On each turn, a player chooses a divisor x of n and replaces n with n-x. Return true if Alice wins.

Hexadecimal and Hexatrigesimal Conversion

Thu, 01 Aug 2024 00:00:00 GMT

Convert a given hexadecimal string to its equivalent representation in base 36 (hexatrigesimal).

Find Missing and Repeated Values

Wed, 31 Jul 2024 00:00:00 GMT

Find the repeated and missing numbers in an n x n grid containing values from 1 to n².

Special Positions in a Binary Matrix

Mon, 29 Jul 2024 00:00:00 GMT

Count positions in a binary matrix where the element is 1 and all other elements in its row and column are 0.

Best Poker Hand

Sun, 28 Jul 2024 00:00:00 GMT

Determine the best poker hand (Flush, Three of a Kind, Pair, or High Card) from 5 cards given their ranks and suits.

Find the Number of Good Pairs I

Sat, 27 Jul 2024 00:00:00 GMT

Given two integer arrays nums1 and nums2 and an integer k, return the number of pairs (i, j) such that nums1[i] is divisible by nums2[j] * k.

Island Perimeter

Sat, 27 Jul 2024 00:00:00 GMT

Calculate the perimeter of the island in a grid where 1 is land and 0 is water. The grid is surrounded by water and contains exactly one island.

Time Needed to Buy Tickets

Fri, 26 Jul 2024 00:00:00 GMT

Calculate the total time taken for the person at position k to finish buying tickets in a queue where people cycle back after buying one.

Water Bottles

Thu, 25 Jul 2024 00:00:00 GMT

Calculate the total number of water bottles you can drink given initial bottles and exchange rate.

Maximum Nesting Depth of the Parentheses

Thu, 25 Jul 2024 00:00:00 GMT

Find the maximum nesting depth of parentheses in a valid string.

Row With Maximum Ones

Tue, 23 Jul 2024 00:00:00 GMT

Find the row with the most 1s in a binary matrix. Return the smallest index if tied.

Minimum Recolors to Get K Consecutive Black Blocks

Mon, 22 Jul 2024 00:00:00 GMT

Find the minimum number of 'W' to 'B' changes needed to create a segment of k consecutive 'B' blocks.

Monotonic Array

Mon, 22 Jul 2024 00:00:00 GMT

An array is monotonic if it is either entirely non-increasing or non-decreasing. Check if the given array satisfies this property.

Find if Path Exists in Graph

Sun, 21 Jul 2024 00:00:00 GMT

Determine if a valid path exists between a source and destination node in an undirected graph using DFS, BFS, or Union-Find.

Set Mismatch

Sat, 20 Jul 2024 00:00:00 GMT

Find the duplicate and missing number in an array containing 1 to n

Maximize Expression of Three Elements

Fri, 19 Jul 2024 00:00:00 GMT

Find the maximum value of (nums[i] - nums[j]) * nums[k] for i < j < k.

Count Pairs Whose Sum is Less than Target

Thu, 18 Jul 2024 00:00:00 GMT

Given an array of integers and a target, count the number of index pairs (i, j) where i < j and the sum of the elements is less than the target.

Smallest Missing Integer Greater Than Sequential Prefix Sum

Thu, 18 Jul 2024 00:00:00 GMT

Find the smallest missing integer greater than the sum of the longest sequential prefix of the array.

First Unique Even Element

Wed, 17 Jul 2024 00:00:00 GMT

Find the first unique even element in an array. A unique element appears exactly once.

Make The String Great

Tue, 16 Jul 2024 00:00:00 GMT

Remove adjacent characters that are the same letter but different case until the string is great.

Unique Email Addresses

Tue, 16 Jul 2024 00:00:00 GMT

Count unique email addresses after applying rules: ignore dots in local name and ignore everything after a plus sign.

Find Products with Valid Serial Numbers

Sat, 13 Jul 2024 00:00:00 GMT

Find all products with valid serial numbers that contain only alphanumeric characters.

Distribute Elements Into Two Arrays I

Sun, 07 Jul 2024 00:00:00 GMT

Distribute elements into two arrays based on the comparison of their last elements and return the concatenation.

Weighted Word Mapping

Sun, 07 Jul 2024 00:00:00 GMT

Calculate the sum of alphabetical weights for the first k characters of a string.

Find Valid Pair of Adjacent Digits in String

Thu, 04 Jul 2024 00:00:00 GMT

Find the first adjacent pair of digits summing to 10, remove them, and return the resulting string.

Complement of Base 10 Integer

Wed, 03 Jul 2024 00:00:00 GMT

The complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.

Special Array With X Elements Greater Than or Equal X

Wed, 03 Jul 2024 00:00:00 GMT

Find the largest integer x such that exactly x elements in the array are greater than or equal to x.

Closest Binary Search Tree Value

Tue, 02 Jul 2024 00:00:00 GMT

Find the value in a BST that is closest to a given target value.

Count Substrings That Satisfy K-Constraint I

Tue, 02 Jul 2024 00:00:00 GMT

Count the number of substrings in a binary string where the count of 0s or 1s is at most k.

Arranging Coins

Mon, 01 Jul 2024 00:00:00 GMT

You have n coins and you want to build a staircase. Find the total number of full rows of the staircase you can build.

A Number After a Double Reversal

Sat, 29 Jun 2024 00:00:00 GMT

Check if reversing a number twice returns the original number. Leading zeros are dropped during reversal.

Count Odd Numbers in an Interval Range

Fri, 28 Jun 2024 00:00:00 GMT

Given two non-negative integers low and high, return the count of odd numbers between low and high (inclusive).

Find Minimum Operations to Make All Elements Divisible by Three

Fri, 28 Jun 2024 00:00:00 GMT

Calculate the minimum operations needed to make all array elements divisible by 3 by adding or subtracting 1.

Image Smoother

Thu, 27 Jun 2024 00:00:00 GMT

An image smoother calculates the average of surrounding cells for each pixel in a matrix.

Can Place Flowers

Tue, 25 Jun 2024 00:00:00 GMT

Determine if n new flowers can be planted in a flowerbed without violating the no-adjacent-flowers rule.

Calculator with Method Chaining

Mon, 24 Jun 2024 00:00:00 GMT

Design a Calculator class that supports method chaining for arithmetic operations like add, subtract, multiply, divide, and power.

Find the Maximum Achievable Number

Mon, 24 Jun 2024 00:00:00 GMT

Given integers num and t, find the maximum x such that after incrementing num t times and decrementing x t times, they are equal.

PromptWhiz Project

Mon, 24 Jun 2024 00:00:00 GMT

A tool for generating creative writing prompts.

Can Make Arithmetic Progression From Sequence

Sat, 22 Jun 2024 00:00:00 GMT

Check if an array can be rearranged to form an arithmetic progression.

Count Equal and Divisible Pairs in an Array

Sat, 22 Jun 2024 00:00:00 GMT

Count pairs (i, j) where i < j, nums[i] == nums[j], and (i * j) is divisible by k.

Check if One String Swap Can Make Strings Equal

Thu, 20 Jun 2024 00:00:00 GMT

You are given two strings s1 and s2. Return true if you can swap two letters in s1 so the result is equal to s2, otherwise return false.

Count Binary Substrings

Thu, 20 Jun 2024 00:00:00 GMT

Count the number of substrings where the number of 0s equals the number of 1s and all 0s and 1s are grouped together.

Search in a Binary Search Tree

Wed, 19 Jun 2024 00:00:00 GMT

Find the node with a given value in a Binary Search Tree and return the subtree rooted at that node.

Count Integers With Even Digit Sum

Tue, 18 Jun 2024 00:00:00 GMT

Given a positive integer num, return the count of integers in [1, num] with an even sum of digits.

Tindog Project

Mon, 17 Jun 2024 00:00:00 GMT

A mockup website for a fictional dog-tinder application.

Count Negative Numbers in a Sorted Matrix

Fri, 14 Jun 2024 00:00:00 GMT

Given a matrix sorted in non-increasing order row-wise and column-wise, return the count of negative numbers.

Toggle Light Bulbs

Wed, 12 Jun 2024 00:00:00 GMT

Given n bulbs and a list of operations, toggle the specified bulbs and return the number of bulbs that remain on.

Minimum Pair Removal to Sort Array I

Mon, 10 Jun 2024 00:00:00 GMT

Find the minimum number of adjacent pair removals required to make an array sorted in non-decreasing order.

Capitalize the Title

Fri, 07 Jun 2024 00:00:00 GMT

Capitalize words in a title: words longer than 2 characters have first letter uppercase, rest lowercase; words of 1-2 characters are all lowercase.

Get the Size of a DataFrame

Fri, 07 Jun 2024 00:00:00 GMT

Calculate the total number of elements in a DataFrame by multiplying its row count by its column count.

Find the Distance Value Between Two Arrays

Wed, 05 Jun 2024 00:00:00 GMT

Count elements in arr1 where no element in arr2 is within distance d.

Strong Password Checker II

Mon, 03 Jun 2024 00:00:00 GMT

Check if a password is strong based on length, character types, and no consecutive identical characters.

Drop Duplicate Rows

Mon, 03 Jun 2024 00:00:00 GMT

Remove duplicate rows from a dataset, keeping only the first occurrence of each unique row.

Maximum Number of Words You Can Type

Sat, 01 Jun 2024 00:00:00 GMT

Count how many words in a text can be typed without using any of the specified broken letters.

Count Square Sum Triples

Thu, 30 May 2024 00:00:00 GMT

Count the number of triples (a,b,c) where a² + b² = c² and all values are between 1 and n.

Count Commas in Range

Wed, 29 May 2024 00:00:00 GMT

Count the total number of commas used when writing all numbers in a range with standard thousand separators.

Type of Triangle

Mon, 27 May 2024 00:00:00 GMT

Determine the type of triangle (equilateral, isosceles, scalene, or none) formed by the first three elements of an array.

Minimum Changes To Make Alternating Binary String

Sun, 26 May 2024 00:00:00 GMT

Find minimum operations to make binary string alternating by flipping characters.

Group Sold Products By The Date

Sat, 25 May 2024 00:00:00 GMT

Write a solution to group products sold by date, counting distinct items and listing them in a comma-separated string.

Percentage of Letter in String

Fri, 24 May 2024 00:00:00 GMT

Given a string and a letter, calculate the percentage of the string composed of that letter, rounded down.

Maximum Number of Operations With the Same Score I

Fri, 24 May 2024 00:00:00 GMT

Find the maximum number of operations where the sum of pairs of elements remains constant.

Max Consecutive Ones

Thu, 23 May 2024 00:00:00 GMT

Given a binary array nums, return the maximum number of consecutive 1s in the array.

Prime In Diagonal

Wed, 22 May 2024 00:00:00 GMT

Find the largest prime number located on either the main diagonal or the anti-diagonal of a square matrix.

Check if The Number is Fascinating

Wed, 22 May 2024 00:00:00 GMT

Check if concatenating n, 2*n, and 3*n produces a number containing digits 1-9 exactly once.

Modify Columns

Tue, 21 May 2024 00:00:00 GMT

Modify the data type of a specific column in a 2D array from string to integer.

Lemonade Change

Tue, 21 May 2024 00:00:00 GMT

Determine if you can provide correct change to all customers at a lemonade stand where each lemonade costs $5.

Degree of an Array

Mon, 20 May 2024 00:00:00 GMT

Find the smallest length of a contiguous subarray that has the same degree as the original array.

Sum of Root To Leaf Binary Numbers

Wed, 15 May 2024 00:00:00 GMT

Calculate the sum of all root-to-leaf binary numbers in a binary tree where nodes contain 0 or 1.

Convert Sorted Array to Binary Search Tree

Mon, 13 May 2024 00:00:00 GMT

Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.

Sort Array by Increasing Frequency

Fri, 10 May 2024 00:00:00 GMT

Sort an array based on the frequency of values, with ties broken by decreasing value.

Maximum Sum With Exactly K Elements

Thu, 09 May 2024 00:00:00 GMT

Pick exactly K elements from an array, incrementing each by 1 after selection, to maximize the total sum.

Minimum Absolute Difference Between Two Values

Thu, 09 May 2024 00:00:00 GMT

Find the minimum absolute difference between any two elements in an array where the distance between their indices is at least k.

Longest Harmonious Subsequence

Wed, 08 May 2024 00:00:00 GMT

Find the length of the longest harmonious subsequence where the difference between max and min is exactly 1.

Check if Matrix Is X-Matrix

Mon, 06 May 2024 00:00:00 GMT

A square matrix is an X-Matrix if all diagonal elements are non-zero and all other elements are zero.

Calculate Amount Paid in Taxes

Sat, 04 May 2024 00:00:00 GMT

Calculate the total tax paid based on progressive tax brackets and a given income.

Make Array Elements Equal to Zero

Fri, 03 May 2024 00:00:00 GMT

You are given an integer array nums. In one operation, select i where nums[i] > 0, subtract 1 from nums[i] and all elements to its right. Return the minimum operations to make all elements zero.

Power of Four

Fri, 03 May 2024 00:00:00 GMT

Given an integer n, return true if it is a power of four, otherwise return false.

N-ary Tree Preorder Traversal

Fri, 03 May 2024 00:00:00 GMT

Given the root of an n-ary tree, return the preorder traversal of its nodes' values.

Find the K-th Character in String Game I

Wed, 01 May 2024 00:00:00 GMT

Alice generates a string by repeatedly replacing characters with themselves and the next alphabet letter. Find the k-th character.

Number of Senior Citizens

Tue, 30 Apr 2024 00:00:00 GMT

Count the number of senior citizens (age > 60) from a list of details strings where age is encoded at specific positions.

GCD of Odd and Even Sums

Tue, 30 Apr 2024 00:00:00 GMT

Calculate the GCD of sums of elements at odd and even indices in an array.

Smallest Missing Multiple of K

Tue, 30 Apr 2024 00:00:00 GMT

Find the smallest positive multiple of k that is not present in the given array.

Check if Array is Good

Sun, 28 Apr 2024 00:00:00 GMT

Determine if an array is a permutation of [1, 2, ..., n, n].

Minimum Average of Smallest and Largest Elements

Sun, 28 Apr 2024 00:00:00 GMT

Find the minimum average of pairs formed by repeatedly removing the smallest and largest elements from an array.

Create Hello World Function

Fri, 26 Apr 2024 00:00:00 GMT

Write a function createHelloWorld that returns a new function which always returns 'Hello World'.

Minimum Cuts to Divide a Circle

Thu, 25 Apr 2024 00:00:00 GMT

Given a circle, find the minimum number of straight cuts needed to divide it into n equal pieces.

Greatest Common Divisor of Strings

Wed, 24 Apr 2024 00:00:00 GMT

Find the largest string that can be constructed by taking a substring of str1 and str2 multiple times.

Final Prices With a Special Discount in a Shop

Wed, 24 Apr 2024 00:00:00 GMT

Given an array prices, for each item find the first subsequent item with a price <= current item to apply a discount, otherwise keep the price.

Minimum Number of Pushes to Type Word I

Tue, 23 Apr 2024 00:00:00 GMT

Find the minimum number of pushes needed to type a word by optimally mapping letters to phone keypad keys.

Counting Bits

Mon, 22 Apr 2024 00:00:00 GMT

Given an integer n, return an array ans of length n + 1 such that for each i (0 <= i <= n), ans[i] is the number of 1's in the binary representation of i.

Rearrange Products Table

Sun, 21 Apr 2024 00:00:00 GMT

Transform a products table with store columns into rows of product-store pairs.

Remove Digit From Number to Maximize Result

Sun, 21 Apr 2024 00:00:00 GMT

Remove one occurrence of a digit from a number to maximize the resulting value.

Find Indices With Index and Value Difference I

Sun, 21 Apr 2024 00:00:00 GMT

Find indices i and j in an array such that the absolute difference of their indices is at least indexDifference and the absolute difference of their values is at least valueDifference.

Game Play Analysis I

Sun, 21 Apr 2024 00:00:00 GMT

Find the first login date for each player from the Activity table.

Customers Who Never Order

Sat, 20 Apr 2024 00:00:00 GMT

Find the names of customers who have never placed an order using SQL.

Minimum Moves to Convert String

Sat, 20 Apr 2024 00:00:00 GMT

Find the minimum moves to convert all 'X' characters to 'O' by changing three consecutive characters at a time.

Maximum Difference by Remapping a Digit

Sat, 20 Apr 2024 00:00:00 GMT

You are given an integer num. Remap one digit to maximize num1 and remap one digit to minimize num2. Return num1 - num2.

Harshad Number

Fri, 19 Apr 2024 00:00:00 GMT

Check if a number is divisible by the sum of its digits and return the sum if true, otherwise -1.

Positions of Large Groups

Thu, 18 Apr 2024 00:00:00 GMT

Find start and end indices of groups of 3 or more consecutive identical characters in a string.

Determine the Winner of a Bowling Game

Wed, 17 Apr 2024 00:00:00 GMT

Calculate scores for two players in a bowling game where knocking down 10 pins doubles the next two scores, then determine the winner.

Power of Three

Tue, 16 Apr 2024 00:00:00 GMT

Given an integer n, return true if it is a power of three. Otherwise, return false.

Reverse String Prefix

Mon, 15 Apr 2024 00:00:00 GMT

Reverse the segment of the string starting from index 0 up to the first occurrence of a specific character.

Valid Word

Fri, 12 Apr 2024 00:00:00 GMT

Determine if a word is valid based on length, character composition, and vowel/consonant requirements.

Longest Uncommon Subsequence I

Fri, 12 Apr 2024 00:00:00 GMT

Given two strings, find the length of the longest subsequence that is not common to both strings.

Compute Alternating Sum

Thu, 11 Apr 2024 00:00:00 GMT

Calculate the alternating sum of an integer array where signs alternate between positive and negative starting with positive.

Range Addition II

Thu, 11 Apr 2024 00:00:00 GMT

Given an m x n matrix and operations incrementing submatrices from (0,0), find the count of maximum integers.

Find Numbers with Even Number of Digits

Mon, 08 Apr 2024 00:00:00 GMT

Given an array of integers, return how many of them contain an even number of digits.

Occurrences After Bigram

Sun, 07 Apr 2024 00:00:00 GMT

Find all words that occur immediately after a given bigram (two consecutive words) in a text.

Maximum Value of a String in an Array

Sun, 07 Apr 2024 00:00:00 GMT

Find the maximum value in an array where numeric strings represent their integer value and non-numeric strings represent their length.

Logger Rate Limiter

Fri, 05 Apr 2024 00:00:00 GMT

Design a logger system that restricts printing the same message within a 10-second window.

Long Pressed Name

Fri, 05 Apr 2024 00:00:00 GMT

Determine if a typed string could be the result of long-pressing keys while typing a target name.

Count Common Words With One Occurrence

Wed, 03 Apr 2024 00:00:00 GMT

Given two string arrays, return the count of strings that appear exactly once in each array.

Permutation Difference between Two Strings

Wed, 03 Apr 2024 00:00:00 GMT

Calculate the sum of absolute differences between indices of each character in two strings where one is a permutation of the other.

Shift 2D Grid

Tue, 02 Apr 2024 00:00:00 GMT

Shift all elements of the 2D grid to the right by k steps, moving elements to the beginning of the grid when they reach the end.

Remove Linked List Elements

Tue, 02 Apr 2024 00:00:00 GMT

Given the head of a linked list and an integer val, remove all nodes with Node.val == val and return the new head.

Top Travellers

Mon, 01 Apr 2024 00:00:00 GMT

Write a SQL query to report the distance travelled by each user, handling users with no rides.

Best Time to Buy and Sell Stock

Sat, 30 Mar 2024 00:00:00 GMT

You are given an array prices where prices[i] is the price of a given stock on the ith day. You want to maximize your profit by choosing a single day to buy and a different day in the future to sell.

Sum of Left Leaves

Sat, 30 Mar 2024 00:00:00 GMT

Find the sum of all left leaves in a binary tree. A left leaf is a node that is a left child of its parent and has no children.

Find Greatest Common Divisor of Array

Fri, 29 Mar 2024 00:00:00 GMT

Find the greatest common divisor of the smallest and largest numbers in an integer array.

Valid Boomerang

Wed, 27 Mar 2024 00:00:00 GMT

Determine if three points are distinct and non-collinear to form a boomerang.

Find if Digit Game Can Be Won

Wed, 27 Mar 2024 00:00:00 GMT

Determine the winner of a turn-based game where Alice picks from even indices and Bob from odd indices based on digit parity.

Add to Array-Form of Integer

Mon, 25 Mar 2024 00:00:00 GMT

The array-form of an integer is an array representing its digits. Add an integer k to the array-form of an integer num.

Button with Longest Push Time

Sun, 24 Mar 2024 00:00:00 GMT

Find the index of the button with the longest push duration in an array. Return the smallest index in case of a tie.

Bank Account Summary II

Fri, 22 Mar 2024 00:00:00 GMT

Report the name and balance of US users with a positive net balance.

Fair Candy Swap

Fri, 22 Mar 2024 00:00:00 GMT

Alice and Bob have different total candies. Exchange one candy box each so they have the same total amount.

Remove All Adjacent Duplicates In String

Thu, 21 Mar 2024 00:00:00 GMT

Remove adjacent duplicates from a string repeatedly until no duplicates remain. Return the final string.

Apply Operations to an Array

Mon, 18 Mar 2024 00:00:00 GMT

Apply operations to adjacent equal elements, then shift all zeros to the end of the array.

Number of Equivalent Domino Pairs

Sun, 17 Mar 2024 00:00:00 GMT

Given a list of dominoes, count the number of pairs (i, j) where i < j and dominoes[i] is equivalent to dominoes[j].

Reverse Bits

Sun, 17 Mar 2024 00:00:00 GMT

Reverse bits of a given 32 bits unsigned integer.

Check if Number Has Equal Digit Count and Digit Value

Sun, 17 Mar 2024 00:00:00 GMT

Determine if a string of digits is valid where the digit at index i equals the count of digit i in the string.

Add Binary

Sun, 17 Mar 2024 00:00:00 GMT

Given two binary strings a and b, return their sum as a binary string.

Shortest Completing Word

Thu, 14 Mar 2024 00:00:00 GMT

Find the shortest word from a list that contains all letters from a license plate.

Plus One

Wed, 13 Mar 2024 00:00:00 GMT

Increment the large integer represented as an integer array by one and return the resulting array of digits.

Count Tested Devices After Test Operations

Tue, 12 Mar 2024 00:00:00 GMT

Count devices with positive battery after iteratively decrementing subsequent devices.

Detect Pattern of Length M Repeated K or More Times

Mon, 11 Mar 2024 00:00:00 GMT

Check if an array contains a pattern of length M repeated K or more times consecutively.

Minimum Deletions for At Most K Distinct Characters

Mon, 11 Mar 2024 00:00:00 GMT

Find the minimum number of deletions required to make a string contain at most K distinct characters.

Sum Multiples

Fri, 08 Mar 2024 00:00:00 GMT

Given a positive integer n, return the sum of all numbers in the range [1, n] inclusive that are divisible by 3, 5, or 7.

Number of Steps to Reduce a Number to Zero

Wed, 06 Mar 2024 00:00:00 GMT

Given an integer num, return the number of steps to reduce it to zero. If even, divide by 2; otherwise, subtract 1.

Employees Whose Manager Left the Company

Wed, 06 Mar 2024 00:00:00 GMT

Find employees earning under $30k whose manager is no longer in the company records.

Vowel-Consonant Score

Sun, 03 Mar 2024 00:00:00 GMT

Given a string s and integer k, find the maximum score of any substring of length k where vowels are worth 1 and consonants are worth 2.

Cousins in Binary Tree

Sun, 03 Mar 2024 00:00:00 GMT

Check if two nodes in a binary tree are cousins (same depth, different parents).

Rename Columns

Sat, 02 Mar 2024 00:00:00 GMT

Rename DataFrame columns from snake_case to Title Case format

Split a String in Balanced Strings

Fri, 01 Mar 2024 00:00:00 GMT

Split a balanced string into the maximum number of balanced substrings using greedy counting.

X of a Kind in a Deck of Cards

Thu, 29 Feb 2024 00:00:00 GMT

Check if a deck of cards can be partitioned into groups of equal size where each group consists of identical cards.

Substring Matching Pattern

Wed, 28 Feb 2024 00:00:00 GMT

Given two strings s and p, return the index of the first occurrence of p in s, or -1 if p is not part of s.

Matrix Cells in Distance Order

Mon, 26 Feb 2024 00:00:00 GMT

Return all matrix coordinates sorted by their Manhattan distance from a center cell.

Find the Losers of the Circular Game

Sun, 25 Feb 2024 00:00:00 GMT

Identify friends who never receive the ball in a circular game where the ball is passed with increasing steps.

Maximum Subarray With Equal Products

Sun, 25 Feb 2024 00:00:00 GMT

Find the maximum length of a subarray where the product of the first half equals the product of the second half.

Count Monobit Integers

Sat, 24 Feb 2024 00:00:00 GMT

Count integers in [0, n] whose binary representation consists of only 0s or only 1s.

Check if Binary String Has at Most One Segment of Ones

Thu, 22 Feb 2024 00:00:00 GMT

Given a binary string s, return true if it contains at most one contiguous segment of '1's.

Finding 3-Digit Even Numbers

Thu, 22 Feb 2024 00:00:00 GMT

Given an array of digits, return all unique 3-digit even numbers that can be formed using each digit at most once.

Minimum Cost to Move Chips to The Same Position

Wed, 21 Feb 2024 00:00:00 GMT

Find minimum cost to move all chips to the same position where moving 2 positions costs 0 and moving 1 position costs 1.

Mean of Array After Removing Some Elements

Wed, 21 Feb 2024 00:00:00 GMT

Given an integer array, remove the smallest 5% and largest 5% of elements and return the average of the remaining elements.

Kth Largest Element in a Stream

Wed, 21 Feb 2024 00:00:00 GMT

Design a class to find the kth largest element in a stream of numbers using a min-heap or sorting.

Sort Array By Parity II

Wed, 21 Feb 2024 00:00:00 GMT

Given an array of integers where half are even and half are odd, sort the array so that every even index contains an even number and every odd index contains an odd number.

Create Target Array in the Given Order

Mon, 19 Feb 2024 00:00:00 GMT

Given two arrays, create a target array by inserting elements at specified indices.

Clear Digits

Mon, 19 Feb 2024 00:00:00 GMT

Remove digits and their immediate left non-digit neighbors from a string until no digits remain.

Count Subarrays of Length Three With a Condition

Mon, 19 Feb 2024 00:00:00 GMT

Count subarrays of length 3 where the middle element is strictly greater than its neighbors.

Height Checker

Sun, 18 Feb 2024 00:00:00 GMT

Count how many students are not standing in the correct position when arranged by height in non-decreasing order.

Remove Palindromic Subsequences

Sun, 18 Feb 2024 00:00:00 GMT

Given a string s consisting only of letters 'a' and 'b', return the minimum number of steps to make the string empty.

Increasing Order Search Tree

Sun, 18 Feb 2024 00:00:00 GMT

Rearrange a binary search tree into a right-skewed tree with increasing order values.

Find the Longest Balanced Substring of a Binary String

Wed, 14 Feb 2024 00:00:00 GMT

Find the longest substring of a binary string where zeros and ones are grouped together and equal in number.

Special Array I

Wed, 14 Feb 2024 00:00:00 GMT

Determine if an array is special by checking if every pair of adjacent elements has different parity.

Find the Original Typed String I

Wed, 14 Feb 2024 00:00:00 GMT

Determine if a typed string is a valid expansion of a target string with repeated characters, returning the total key presses or 0.

Convert a Number to Hexadecimal

Wed, 14 Feb 2024 00:00:00 GMT

Given an integer, return its hexadecimal string representation using two's complement for negatives.

Check if Every Row and Column Contains All Numbers

Mon, 12 Feb 2024 00:00:00 GMT

Determine if an n x n matrix is a valid Latin square where every row and column contains all numbers from 1 to n.

Reformat Date

Sun, 11 Feb 2024 00:00:00 GMT

Convert a date from 'Day Month Year' format to 'YYYY-MM-DD' format.

Two Furthest Houses With Different Colors

Sun, 11 Feb 2024 00:00:00 GMT

Find the maximum distance between two houses with different colors in a street represented by an array.

Design Neighbor Sum Service

Sun, 11 Feb 2024 00:00:00 GMT

Design a service to calculate adjacent and diagonal neighbor sums for values in an n x n grid.

Self Dividing Numbers

Sun, 11 Feb 2024 00:00:00 GMT

A self-dividing number is divisible by every digit it contains. Return all self-dividing numbers in the range [left, right].

Number of Unequal Triplets in Array

Fri, 09 Feb 2024 00:00:00 GMT

Count the number of index triplets (i, j, k) where i < j < k and all three corresponding values are distinct.

Left and Right Sum Differences

Fri, 09 Feb 2024 00:00:00 GMT

Given an integer array nums, return the difference array where each element is the absolute difference between the sum of elements to its left and the sum of elements to its right.

Minimum Number Game

Wed, 07 Feb 2024 00:00:00 GMT

You are given an array of even length. Alice and Bob take turns removing the smallest remaining numbers, swapping them, and appending them to a result array. Return the resulting array.

Valid Perfect Square

Mon, 05 Feb 2024 00:00:00 GMT

Given a positive integer num, return true if num is a perfect square or false otherwise.

Maximum Number of Balls in a Box

Sun, 04 Feb 2024 00:00:00 GMT

Count balls in boxes based on digit sum of ball numbers and find the box with maximum balls.

Determine Whether Matrix Can Be Obtained By Rotation

Sun, 04 Feb 2024 00:00:00 GMT

Check if one n x n matrix can be transformed into another by rotating it 90 degrees clockwise any number of times.

Range Sum Query - Immutable

Fri, 02 Feb 2024 00:00:00 GMT

Design a class to efficiently calculate the sum of elements between two indices in an immutable array.

Largest Triangle Area

Fri, 02 Feb 2024 00:00:00 GMT

Given a set of points on a 2D plane, find the maximum area of a triangle that can be formed from any three points.

Display the First Three Rows

Mon, 29 Jan 2024 00:00:00 GMT

Write a solution to display the first three rows of a DataFrame.

Reverse Words in a String III

Fri, 26 Jan 2024 00:00:00 GMT

Given a string s, reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

N-ary Tree Postorder Traversal

Fri, 26 Jan 2024 00:00:00 GMT

Given the root of an n-ary tree, return the postorder traversal of its nodes' values.

Power of Two

Tue, 23 Jan 2024 00:00:00 GMT

Given an integer n, return true if it is a power of two. Otherwise return false.

Invalid Tweets

Mon, 22 Jan 2024 00:00:00 GMT

Find the IDs of tweets where the content length exceeds 15 characters.

Find Books with No Available Copies

Mon, 22 Jan 2024 00:00:00 GMT

Identify books in a library system that currently have zero copies available for borrowing.

Split the Array

Sun, 21 Jan 2024 00:00:00 GMT

Check if an array can be split into two parts where no element appears more than once in either part.

Kth Missing Positive Number

Thu, 18 Jan 2024 00:00:00 GMT

Given an array arr of positive integers sorted in strictly increasing order, and an integer k, return the kth positive integer that is missing from this array.

Latest Time by Replacing Hidden Digits

Thu, 18 Jan 2024 00:00:00 GMT

Given a time string with hidden digits, find the latest valid time by replacing the hidden digits.

Count Partitions with Even Sum Difference

Wed, 17 Jan 2024 00:00:00 GMT

Count the number of ways to partition an array into two non-empty contiguous parts such that the absolute difference of their sums is even.

Convert Date to Binary

Tue, 16 Jan 2024 00:00:00 GMT

Convert a date string from decimal format to binary format by converting year, month, and day separately.

Maximum Depth of N-ary Tree

Tue, 16 Jan 2024 00:00:00 GMT

Given a n-ary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Replace Employee ID With The Unique Identifier

Sun, 14 Jan 2024 00:00:00 GMT

Write a SQL query to show the unique_id of each employee along with their name, displaying null if no unique_id exists.

Detect Capital

Sun, 14 Jan 2024 00:00:00 GMT

Determine if a word uses capital letters correctly: all uppercase, all lowercase, or only the first letter uppercase.

Generate a String With Characters That Have Odd Counts

Sat, 13 Jan 2024 00:00:00 GMT

Given an integer n, return a string of length n with all lowercase English letters such that each character appears an odd number of times.

Delete Greatest Value in Each Row

Sat, 13 Jan 2024 00:00:00 GMT

Delete the greatest value from each row in each operation, add the max of deleted values to answer, repeat until grid is empty.

Delete Columns to Make Sorted

Sat, 13 Jan 2024 00:00:00 GMT

You are given an array of strings of the same length. Determine the number of columns that are not sorted lexicographically.

Calculate Money in Leetcode Bank

Wed, 10 Jan 2024 00:00:00 GMT

Calculate total money saved after n days with increasing daily deposits that reset weekly.

Check if All A's Appears Before All B's

Wed, 10 Jan 2024 00:00:00 GMT

Given a string s consisting of only characters 'a' and 'b', return true if every 'a' appears before every 'b'.

Minimize String Length

Fri, 05 Jan 2024 00:00:00 GMT

Given a string s, return the minimum possible length after deleting characters that appear more than once.

Verifying an Alien Dictionary

Fri, 05 Jan 2024 00:00:00 GMT

Determine if words are sorted according to a custom alien alphabet order.

Bitwise OR of Even Numbers in an Array

Wed, 03 Jan 2024 00:00:00 GMT

Calculate the bitwise OR of all even numbers present in the given integer array.

Minimum Time to Type Word Using Special Typewriter

Tue, 02 Jan 2024 00:00:00 GMT

Calculate the minimum time to type a word on a circular typewriter where moving the pointer and typing each take 1 second.

Find the Pivot Integer

Mon, 01 Jan 2024 00:00:00 GMT

Find the integer x where sum of 1 to x equals sum of x to n, or return -1.

Reverse Letters Then Special Characters in a String

Mon, 01 Jan 2024 00:00:00 GMT

Reverse only the letters in a string while keeping special characters in their original positions.