dbu50120-优快云博客

转载 LeetCode: Gray Code

The gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integernrepresenting the total number of bits in the code, print the sequence ...

2014-09-24 15:15:00 132

转载 LeetCode: 4sum

Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.Note:Elements...

2014-08-24 22:32:00 146

转载 LeetCode：3Sum Closest

Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have ex...

2014-08-24 18:10:00 182

转载 LeetCode：Remove Element

Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn't matter what you leave beyond the new length....

2014-07-05 14:50:00 137

转载 LeetCode: Longest Substring Without Repeating Characters

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....

2014-07-03 22:24:00 69

转载 LeetCode：Longest Consecutive Sequence

Given an unsorted array of integers, find the length of the longest consecutive elements sequence.For example,Given[100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is[1, 2, 3,...

2014-07-02 22:03:00 89

转载 LeetCode:Longest Common Prefix

Longest Common PrefixWrite a function to find the longest common prefix string amongst an array of strings.Solution：public class Solution { public String longestCommonPrefix(String[]...

2014-06-28 23:04:00 57

转载 LeetCode：Longest Palindromic Substring

Longest Palindromic SubstringGiven a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there exists one unique longest pa...

2014-06-28 21:20:00 155

转载 LeetCode:Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.click to show spoilers.Some hints:Could negative integers be palindromes? (ie, -1)If you are thinking of converti...

2014-06-22 14:14:00 93

转载 LeetCode:Container With Most Water

Givennnon-negative integersa1,a2, ...,an, where each represents a point at coordinate (i,ai).nvertical lines are drawn such that the two endpoints of lineiis at (i,ai) and (i, 0). Find...

2014-06-22 12:56:00 88

转载 LeetCode:Reverse Integer

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 codi...

2014-06-21 09:31:00 52

转载 LeetCode: Add Two Numbers

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...

2014-06-19 23:06:00 50

转载 LeetCode: Palindrome Partitioning

Given a strings, partitionssuch that every substring of the partition is a palindrome.Return all possible palindrome partitioning ofs.For example, givens="aab",Return [ ...

2014-04-06 15:13:00 107

转载 Valid Palindrome

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Panama"is a palindrome."race a car"isnota p...

2014-04-04 11:05:00 46

转载 LeetCode： Path Sum 2

Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree andsum = 22, 5 ...

2014-03-31 21:29:00 167

转载 LeetCode: Path Sum

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.For example:Given the below binary tree ands...

2014-03-24 22:41:00 62

转载 LeetCode：Convert Sorted Array to Binary Search Tree

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.Solution：BinaryTree* sortedArrayToBST(int arr[], int start, int end) { if (start > end...

2014-03-23 17:35:00 95

转载 LeetCode:Convert Sorted List to Binary Search Tree

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.Solution:/** * Definition for singly-linked list. * struct ListNode { * ...

2014-03-23 17:20:00 102

转载 LeetCode: Balanced Binary Tree

Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never di...

2014-03-23 15:14:00 86

转载 LeetCode: Maximum Depth of Binary Tree

Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.递归版本：class Solution {public...

2014-03-06 22:13:00 91

转载 LeetCode:Merge Sorted Array

Given two sorted integer arrays A and B, merge B into A as one sorted array.Note:You may assume that A has enough space (size that is greater or equal to m + n) to hold additional elements fr...

2014-03-06 21:08:00 118

转载 LeetCode:Single Number II

Given an array of integers, every element appearsthreetimes except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without us...

2014-03-06 17:13:00 89

转载 LeetCode: Single Number

Given an array of integers, every element appearstwiceexcept for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without using ex...

2014-03-06 15:35:00 83

转载 LeetCode:3Sum

Given an arraySofnintegers, are there elementsa,b,cinSsuch thata+b+c= 0? Find all unique triplets in the array which gives the sum of zero.Note:Elements in a tripl...

2014-03-05 22:06:00 79

转载 LeetCode:Binary Tree Preorder Traversal

Given a binary tree, return thepreordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[1,2,3].Note:Recursive solutio...

2014-03-05 21:18:00 102

转载 LeetCode: Best Time to Buy and Sell Stock III

Say you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the maximum profit. You may complete at mosttwotransactions.Note:You may n...

2014-03-03 16:31:00 80

转载 LeetCode: Best Time to Buy and Sell Stock II

Say you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy...

2014-03-03 14:43:00 117

转载 Best Time to Buy and Sell Stock

Say you have an array for which theithelement is the price of a given stock on dayi.If you were only permitted to complete at most one transaction (ie, buy one and sell one share o...

2014-03-03 12:30:00 83

转载 LeetCode: Pow(x, n)

Pow(x, n)Implement pow(x,n). 1 public class Solution { 2 private double power(double x, int n) { 3 if (n == 0) 4 return 1; 5 double v = power(x, ...

2014-03-02 20:42:00 141

转载 LeetCode: Word Break

Given a stringsand a dictionary of wordsdict, determine ifscan be segmented into a space-separated sequence of one or more dictionary words.For example, givens="leetcode",dict=["leet",...

2014-03-01 16:06:00 94

转载 LeetCode: LRU Cache

Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations:getandset.get(key)- Get the value (will always be positive) of the key ...

2014-03-01 11:38:00 122

转载 LeetCode: Max Points on a Line

Givennpoints on a 2D plane, find the maximum number of points that lie on the same straight line.Solution:/** * Definition for a point. * struct Point { * int x; * ...

2014-02-22 14:56:00 110

转载 LeetCode: Evaluate Reverse Polish Notation

Evaluate the value of an arithmetic expression inReverse Polish Notation.Valid operators are+,-,*,/. Each operand may be an integer or another expression.Some examples: ["2"...

2014-01-05 16:51:00 106

转载 LeetCode：Two Sum

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, ...

2013-12-22 20:58:00 84

转载 LeetCode: Binary Tree Postorder Traversal

Given a binary tree, return thepostordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[3,2,1].Note:Recursive soluti...

2013-12-22 16:37:00 90

转载 LeetCode:Binary Tree Maximum Path Sum

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 3Return6....

2013-12-22 09:49:00 109

转载 iOS开发入门学习总结（二）Objective－C 语法特性总结

Objective－CEncapsulating Data01. atomic // default02. nonatomic03. strong=retain // default04. weak= unsafe_unretained05. retain06. assign ...

2013-12-21 19:28:00 107

转载 LeetCode: Minimum Depth of Binary Tree

Problem:Minimum Depth of Binary TreeGiven a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf n...

2013-12-21 17:27:00 97

转载 iOS开发入门学习总结（－）

这个礼拜应该算是踏上iOS学习的第一个礼拜，有必要对这段学习过程做一个简短的总结。直观感觉：iOS 开发环境给我的直观印象非常cool，XCode许多酷炫的功能，iOS 7 SDK的优良的设计，其极其丰富的api，以及Objective－C 奇特的语法让我觉得非常新鲜有趣。主要按照apple 官方的开发入门指导，完成一个 To－do—List app通过实现这个小proj...

2013-12-12 20:58:00 168

转载 Java 并发编程基础学习

1.Java 并发编程的容器ConcurrentHashMap，HashTable，Collections.synchronizedMap 三者比较。HashTable，Collections.synchronizedMap 提供对hashmap的独占锁，当有一个线程对其remove，add，遍历，等操作时，即使cpu有空闲的资源，也不能访问该容器。可伸缩性比较差。而C...

2013-11-30 23:19:00 53

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