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

Given the root of a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original

You are given an array of non-overlapping intervals intervals where intervals[i] = [starti, endi] represent the start and the end of the ith interval and intervals is sorted

You are given a binary array nums and an integer k. A k-bit flip is choosing a subarray of length k from nums and simultaneously changing every 0 in the subarray to 1, and

Given an array of strings strs, group the anagrams together. You can return the answer in any order. An Anagram is a word or phrase formed

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap

Given an unsorted integer array nums. Return the smallest positive integer that is not present in nums. You must implement an algorithm that runs in O(n) time and