Problem There is a stream of n (idKey, value) pairs arriving in an arbitrary order, where idKey is an integer between 1 and n...

Problem You are given a 0-indexed string array words. Two strings are similar if they consist of the same characters. For ex...

Problem You are given a positive integer n. Let even denote the number of even indices in the binary representation of n with...

Problem Given an integer array sorted in non-decreasing order, there is exactly one integer in the array that occurs more tha...

Problem Given an array arr, replace every element in that array with the greatest element among the elements to its right, an...

Problem You are working in a ball factory where you have n balls numbered from lowLimit up to highLimit inclusive (i.e., n ==...

Problem You are given a string s. Your task is to remove all digits by doing this operation repeatedly: Delete the first dig...

Problem Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique elem...

Problem Given a positive integer n, generate an n x n matrix filled with elements from 1 to n² in spiral order. https://leetc...

Problem Given a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any or...

Problem Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any orde...

Problem You are given two strings s1 and s2 of equal length. A string swap is an operation where you choose two indices in a ...

Problem Given an integer array nums that may contain duplicates, return all possible subsets (the power set). A subset of an...

Problem Given an integer array nums of unique elements, return all possible subsets (the power set). A subset of an array is...

Problem Given an array of positive integers nums, return the maximum possible sum of an ascending subarray in nums. A subarra...

Problem Given an array of integers nums, half of the integers in nums are odd, and the other half are even. Sort the array so...

Problem Given an integer array nums, move all the even integers at the beginning of the array followed by all the odd integer...

Problem You are given an array of integers nums. Return the length of the longest subarray of nums which is either strictly i...

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

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

Problem You are given an m x n matrix M initialized with all 0’s and an array of operations ops, where ops[i] = [aᵢ, bᵢ] mean...

Problem Given a string s and an integer k, reverse the first k characters for every 2k characters counting from the start of ...

Problem Write a function that reverses a string. The input string is given as an array of characters s. You must do this by m...

Problem Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must appe...

Problem Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be u...

Problem Given an integer array nums and an integer k, return true if there are two distinct indices i and j in the array such...

Problem Given an integer numRows, return the first numRows of Pascal’s triangle. In Pascal’s triangle, each number is the sum...

Problem Given an integer rowIndex, return the rowIndexᵗʰ (0-indexed) row of the Pascal’s triangle. In Pascal’s triangle, each...

Problem Given an integer array nums of size n, return the number with the value closest to 0 in nums. If there are multiple a...

Problem You are given an array nums of non-negative integers and an integer k. An array is called special if the bitwise OR o...

Problem You are given a 0-indexed integer array nums, and an integer k. In one operation, you can remove one occurrence of th...

Problem You are given three positive integers num1, num2, and num3. The key of num1, num2, and num3 is defined as a four-digi...