Given a positive integer n, return the number of all possible attendance records with length n, which will be regarded as rewardable. The answer may b ...

You are given a string representing an attendance record for a student. The record only contains the following three characters: ‘A’ : Absent. ‘L’ : ...

Given two arrays, write a function to compute their intersection. ExampleNo.1Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2,2] No.2Input: nums1 = ...

Given two arrays, write a function to compute their intersection. ExampleNo.1Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2] No.2Input: nums1 = [4 ...

In this problem, a rooted tree is a directed graph such that, there is exactly one node (the root) for which all other nodes are descendants of this n ...

In this problem, a tree is an undirected graph that is connected and has no cycles. The given input is a graph that started as a tree with N nodes (wi ...

There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct ...

There are N rooms and you start in room 0. Each room has a distinct number in 0, 1, 2, …, N-1, and each room may have some keys to access the next ro ...

In a given 2D binary array A, there are two islands. (An island is a 4-directionally connected group of 1s not connected to any other 1s.) Now, we ma ...

On an N x N board, the numbers from 1 to N*N are written boustrophedonically starting from the bottom left of the board, and alternating direction eac ...