hechenghai

Largest Rectangle in HistogramMy SubmissionsQuestionTotal Accepted: 49964 Total Submissions: 215334 Difficulty: HardGiven n non-negative integers representing the histogram

Integer to RomanMy SubmissionsQuestion Solution Total Accepted: 44525 Total Submissions: 127649 Difficulty: MediumGiven an integer, convert it to a roman numeral.Input is g

Container With Most WaterTotal Accepted: 52276 Total Submissions: 163550 Difficulty: MediumGiven n non-negative integers a1, a2, ..., an, where each represents a point at coordinat

Roman to IntegerMy SubmissionsQuestion Solution Total Accepted: 56002 Total Submissions: 159037 Difficulty: EasyGiven a roman numeral, convert it to an integer.Input is gua

4SumMy SubmissionsQuestion Solution Total Accepted: 50999 Total Submissions: 230927 Difficulty: MediumGiven an array S of n integers, are there elements a, b, c, and d in S s

Search Insert PositionMy SubmissionsQuestionTotal Accepted: 79962 Total Submissions: 222866 Difficulty: MediumGiven a sorted array and a target value, return the index if the t

Determine whether an integer is a palindrome. Do this without extra space.public class Solution { public boolean isPalindrome(int x) { if(x<0)return false; int a = 1; int b = x;

Reverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -321click to show spoilers.Have you thought about this?Here are some good questions to ask before c

Implement regular expression matching with support for '.' and '*'.'.' Matches any single character.'*' Matches zero or more of the preceding element.The matching should cover the entire inp

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P A H NA P L S I

Longest Common PrefixMy SubmissionsQuestion Solution Total Accepted: 68487 Total Submissions: 264798 Difficulty: EasyWrite a function to find the longest common prefix string

First Missing PositiveMy SubmissionsQuestionTotal Accepted: 51712 Total Submissions: 224707 Difficulty: HardGiven an unsorted integer array, find the first missing positive int

Substring with Concatenation of All WordsMy SubmissionsQuestionTotal Accepted: 42899 Total Submissions: 215720 Difficulty: HardYou are given a string, s, and a list of words, w

Search in Rotated Sorted Array IIMy SubmissionsQuestionTotal Accepted: 50992 Total Submissions: 162671 Difficulty: MediumFollow up for "Search in Rotated Sorted Array":What i

转载地址：http://www.letiantian.me/2014-10-22-mahout-naive-bayes-newsgroups/mahout版本是0.9；hadoop版本是1.2.1。下载数据集20 newsgroups dataset，解压后得到20news-bydate目录：$ cp -R 20news-bydate/*/* 2

A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below).The robot can only move either down or right at any point in time. The robot is trying to reach the

Search for a RangeMy SubmissionsQuestionTotal Accepted: 62397 Total Submissions: 225032 Difficulty: MediumGiven a sorted array of integers, find the starting and ending positio

Search in Rotated Sorted ArrayMy SubmissionsQuestionTotal Accepted: 76870 Total Submissions: 264831 Difficulty: HardSuppose a sorted array is rotated at some pivot unknown to y

Jump Game IIMy SubmissionsQuestionTotal Accepted: 52353 Total Submissions: 213392 Difficulty: HardGiven an array of non-negative integers, you are initially positioned at the f

Decode WaysMy SubmissionsQuestionTotal Accepted: 55371 Total Submissions: 330911 Difficulty: MediumA message containing letters from A-Z is being encoded to numbers using the

转载地址：http://blog.youkuaiyun.com/fengbingyang/article/details/12236121实现浮点类型的幂运算，函数原型为:double pow(double x, int n)下面介绍一下解决该问题的几种方法以及要注意的地方：1)最直观容易想到的方法就是用递归方法求n个x的乘积，注意考虑n的正负号，时间复杂度为O(n)

转载地址：http://www.cnblogs.com/felixfang/p/3708999.html开篇通常的匹配分为两类，一种是正则表达式匹配，pattern包含一些关键字，比如'*'的用法是紧跟在pattern的某个字符后，表示这个字符可以出现任意多次(包括0次)。另一种是通配符匹配，我们在操作系统里搜索文件的时候，用的就是这种匹配。比如 "*.pdf"，'

题目为：Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring.使用动态规划，可以将时间

There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).这个题目实际上就是先用快速排序进行合并，然后求中间

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a link

public class Solution { public int singleNumber(int [] A){ Arrays.sort(A); int n = A.length; for(int i=0;i<n-1;i+=3){ if(!(A[i]==A[i+1]&&A[i+1]==A[i+2])){ if(A[i]==A[i+1]){ return A

https://oj.leetcode.com/problems/copy-list-with-random-pointer/

https://oj.leetcode.com/problems/word-break-ii/zh

https://oj.leetcode.com/problems/linked-list-cycle/

https://oj.leetcode.com/problems/binary-tree-preorder-traversal/

https://oj.leetcode.com/problems/word-break/

https://oj.leetcode.com/problems/linked-list-cycle-ii/接

点https://oj.leetcode.com/problems/binary-tree-postorder-traversal/接

https://oj.leetcode.com/problems/reorder-list/

public class Solution { public int singleNumber(int [] A){ Arrays.sort(A); int n = A.length; for(int i=0;i<n-1;i+=2){ if(A[i]!=A[i+1]){ return A[i]; } } return A[n-1]; }}

https://oj.leetcode.com/problems/candy/

Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors.OJ's undirected graph serialization:Nodes are labeled uniquely.We use # as a separator for each

Given an array of integers, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers such that they add up to the target, whe

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. Fo

Given a binary tree, find the maximum path sum.The path may start and end at any node in the tree.For example:Given the below binary tree, 1 / \ 2 3Return 6.