题目描述 Follow up for “Unique Paths”: Now consider if some obstacles are added to the grids. How many unique path…

1. 题目 Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C w…

题目地址：https://leetcode-cn.com/probl…题目描述：给定一个二维的矩阵，包含 ‘X’ 和 ‘O’（字母 O）。 找到所有被 R…

  Given an array of integers, return indices of the two numbers such that they add up to a spec…

  Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing it…

  Given a positive integer n, return the number of all possible attendance records with length n, which w…

问题 经常使用Javascript的同学一定对setInterval非常熟悉，当使用setInterval(callback, timer)时，每经过timer毫秒时间，系统都将调用一次callback。请问全局如果没有…

题目：将一个数组分成两部分，不要求两部分所包含的元素个数相等，要求使得这两个部分的和的差值最小。比如对于数组{1,0,1,7,2,4}，可以分成{1,0,1,2,4}和{7}，使得这两部分的差值最小。 思路：这个问题可以…

98. Validate Binary Search Tree 题目 Given a binary tree, determine if it is a valid binary search tree (BST). A…

  Suppose that a website contains two tables, the Customers table and the Orders table. Write a SQL query…

  Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Input: 2 / \ 1 3 O…

  Given a list of strings, you need to find the longest uncommon subsequence among them. The longest unco…