Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can…

  Given the radius and x-y positions of the center of a circle, write a function randPoint whic…

  You are standing at position 0 on an infinite number line. There is a goal at position t…

121. Best Time to Buy and Sell Stock 题目 Say you have an array for which the ith element is the price of a give…

  Given a picture consisting of black and white pixels, and a positive integer N, find the number of blac…

Edit Distance Given two words word1 and word2, find the minimum number of steps required to convert word1 to w…

题目地址：https://leetcode-cn.com/probl…题目描述：给出集合 [1,2,3,…,n]，其所有元素共有 n! 种排列。 按大小顺序列出所有排列情况，并一一标记，当 n = 3 时, …

中位数是有序列表中间的数。如果列表长度是偶数，中位数则是中间两个数的平均值。 例如， [2,3,4] 的中位数是 3 [2,3] 的中位数是 (2 + 3) / 2 = 2.5 设计一个支持以下两种操作的数据结…

  Given a binary tree, imagine yourself standing on the right side of it, return the values of …

  Given two integers n and k, you need to construct a list which contains n diff…

题目： Given a string s and a dictionary of words dict, add spaces in s to construct a s…

  Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a…