The API: int read4(char *buf) reads 4 characters at a time from a file. The return value is the actual number …

这个挺直接的，也被李特标了EASY. 就是在1～n里面找第一个出错点。其实就是搜一个数字i（同时用isBadVersion(i)）检查这个数字是否报错。那搜index的活，直接binary search就好了。 注意特别…

1 题目描述 Given a linked list, swap every two adjacent nodes and return its head. Your algorithm should use only …

49. Group Anagrams python 题目： https://leetcode.com/problems/anagrams/ 难度 : Medium 我又来使用我的取巧神奇python大法 “c…

Problem More LeetCode Discussions Factory is a design pattern in common usage. Please implement a ToyFactory w…

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase. 将字…

本文首发于我的个人博客：尾尾部落 题目描述 用两个栈来实现一个队列，完成队列的Push和Pop操作。 队列中的元素为int类型。 解题思路 两个栈 stack1 和 stack2: push 动作都在 stack1 中进…

Medium You are given two non-empty linked lists representing two non-negative integers. The most significant d…

Given a binary search tree and a node in it, find the in-order successor of that node in the BST. If the given…

My code: public class Solution { public int longestPalindrome(String s) { if (s == null || s.length() == 0) { …

Problem Find the contiguous subarray within an array (containing at least one number) which has the largest su…

给定一个只包含 ‘(‘，’)’，'{‘，’}’，'[‘，’]’ 的字符串，推断字符串是不是有用。 有…