Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Fi…

  Given a binary array, find the maximum number of consecutive 1s in this array. Example 1: Input: [1,1,0…

题目： Implement next permutation, which rearranges numbers into the lexicographically next greater permutation o…

Given an array of integers, find out whether there are two distinct indices i and j in the array such that the…

40. Combination Sum II 题目 Given a collection of candidate numbers (C) and a target number (T), find all unique…

  Given two binary trees, write a function to check if they are equal or not. Two binary trees are consid…

  You are playing the following Flip Game with your friend: Given a string that contains only these two c…

  Given a root node reference of a BST and a key, delete the node with the given key in the BST. Return t…

Reverse Integer Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 字符串…

  Given an array A, we may rotate it by a non-negative integer K so that the array becomes…

Write a program to find the n-th ugly number. Ugly numbers are positive numbers whose prime factors only inclu…

  Given a string S, find the length of the longest substring T that contains at most two distinct charact…