Create a timebased key-value store class TimeMap, that supports two operations. set(string key, string value, int timestamp) Stores the key and value ...

In an election, the i-th vote was cast for persons[i] at time times[i]. Now, we would like to implement the following query function: TopVotedCandidat ...

Given a list of sorted characters letters containing only lowercase letters, and given a target letter target, find the smallest element in the list t ...

Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If target exists, ...

Given two integer arrays A and B, return the maximum length of an subarray that appears in both arrays. ExampleInput:A: [1,2,3,2,1]B: [3,2,1,4,7] Outp ...

Given four lists A, B, C, D of integer values, compute how many tuples (i, j, k, l) there are such that A[i] + B[j] + C[k] + D[l] is zero. To make pro ...

On a 2 dimensional grid with R rows and C columns, we start at (r0, c0) facing east. Here, the north-west corner of the grid is at the first row and c ...

Given a positive integer n, generate a square matrix filled with elements from 1 to n^2 in spiral order. ExampleInput: 3 Output: 12345[ [ 1, 2, 3 ], [ ...

On a 2-dimensional grid, there are 4 types of squares: 1 represents the starting square. There is exactly one starting square. 2 represents the endi ...

Given an 2D board, count how many battleships are in it. The battleships are represented with ‘X’s, empty slots are represented with ‘.’s. You may ass ...