Category: c / c++

Given two strings S and T, return if they are equal when both are typed into empty text editors. # means a backspace character. Example 1: Input: S = …

In an alien language, surprisingly they also use english lowercase letters, but possibly in a different order. The order of the alphabet is some permutation of lowercase letters. Given …

Given a 2D integer matrix M representing the gray scale of an image, you need to design a smoother to make the gray scale of each cell becomes the …

Given a binary tree, each node has value 0 or 1. Each root-to-leaf path represents a binary number starting with the most significant bit. For example, if the path …

A valid parentheses string is either empty (“”), “(” + A + “)”, or A + B, where A and B are valid parentheses strings, and + represents string …