You are given a positive integer n representing the number of nodes of a Directed Acyclic Graph (DAG). The nodes are numbered from 0 to n – […]

You are given an integer n denoting the number of cities in a country. The cities are numbered from 0 to n – 1. You

There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly n –

Given an integer array nums of unique elements, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order. Example

Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no

Given an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the

Given the root of a binary search tree, return a balanced binary search tree with the same node values. If there is more than one

You are climbing a staircase. It takes n steps to reach the top. Each time you can either climb 1 or 2 steps. In how many

Given a string s consisting of words and spaces, return the length of the last word in the string. A word is a maximal substring consisting of non-space