bae_-优快云博客

原创 Palindrome Linked List leetcode 234

Given a singly linked list, determine if it is a palindrome.Follow up: Could you do it in O(n) time and O(1) space?判断给定的链表是不是回文的：把要判断的链表分成两部分，将第二部分逆置，逐个与前一部分的val相比较，若不同返回false/** * Definition for sin

2015-07-21 09:31:36 467

原创 Lowest Common Ancestor of a Binary Tree leetcode236

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and

2015-07-13 19:40:44 387

原创 Lowest Common Ancestor of a Binary Search Tree leetcode235

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two

2015-07-11 15:44:03 299

原创 Isomorphic Strings leetcode 205

Given two strings s and t, determine if they are isomorphic.Two strings are isomorphic if the characters in s can be replaced to get t.All occurrences of a character must be replaced with another chara

2015-07-02 22:25:48 318

原创 Longest Common Prefix leetcode 14

Write a function to find the longest common prefix string amongst an array of strings. 找所有字符串的公共前缀，简单地实现题class Solution {public: string strPrefix(string s1,string s2){ if(s1.length()==0||s

2015-06-15 18:14:44 305

原创 Clone Graph Leetcode 133

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 node, an

2015-06-14 22:50:11 321

原创 Distinct Subsequences leetcode 115

Given a string S and a string T, count the number of distinct subsequences of T in S.A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of

2015-06-09 17:55:26 339

原创 Multiply Strings leetcode 43

Given two numbers represented as strings, return multiplication of the numbers as a string.Note: The numbers can be arbitrarily large and are non-negative.经典的大数相乘问题： 1，从给定字符串最后一位开始操作，要弄清楚整个乘法的过程以及各进位的

2015-06-03 23:48:49 462

原创 Edit Distance Leetcode 72

Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)You have the following 3 operations permitted on a word:a) In

2015-06-02 23:31:41 369

原创 Simplify Path Leetcode71

Given an absolute path for a file (Unix-style), simplify it.For example, path = “/home/”, => “/home” path = “/a/./b/../../c/”, => “/c”click to show corner cases. Corner Cases:Did you consider the ca

2015-05-31 00:52:17 470

原创 Minimum Path Sum leetcode 64

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.Note: You can only move either down or right at any

2015-05-28 19:21:46 366

原创 Binary Tree Inorder Traversal leetCode11

Given a binary tree, return the inorder traversal of its nodes’ values.For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,3,2].Note: Recursive solution is trivial,

2015-05-27 19:16:31 283

原创 Longest Substring Without Repeating Characters leetcode3

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. For “

2015-05-24 01:30:48 233

原创 Longest Palindromic Substring leetcode 5

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.求字符串的最长回文串1，从字符串第一个字符开始遍历，向

2015-05-23 13:19:56 301

原创 ZigZag Conversion leetcode6

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 N A P L

2015-05-18 00:22:19 253

原创 Reverse Linked List II Leetcode92

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example: Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note: Given m, n satisfy the followi

2015-05-17 01:50:06 295

原创 Binary Tree Postorder Traversal leetcode145

Given a binary tree, return the postorder traversal of its nodes’ values.For example: Given binary tree {1,#,2,3},1 \ 2 / 3return [3,2,1]. Note: Recursive solution is trivial, cou

2015-05-14 17:27:31 443

原创 Binary Tree Preorder Traversal leetcode144

Given a binary tree, return the preorder traversal of its nodes’ values.For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3].Note: Recursive solution is trivial,

2015-05-10 21:41:13 317

原创 Reverse bits leetcode190

Reverse bits of a given 32 bits unsigned integer.For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110

2015-05-09 23:17:54 328

原创 happy number leetcode202

Write an algorithm to determine if a number is “happy”.A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of i

2015-05-09 22:50:37 383

原创 Reverse Linked List LeetCode206

reverse a singly linked list 题目比较简单，就是反转一个链表.要求用iteratively （迭代）和recursively（递归）解决/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNo

2015-05-07 14:35:48 325

原创字符串查找算法kmp

这样一个问题：给定一个文本串s，和一个匹配串p，要求查找p第一次在s中出现的位置。常见的方法如暴力搜素，逐个匹配s[i],p[j],若匹配，下标后移。不匹配，i回溯到这次匹配前的下一位置，j置为0，重新匹配。最坏情况，时间复杂度O（n*m）。int violenceSearch(char *s,char *p){ int i=0,j=0; int lenp=strl

2015-05-03 21:22:51 691

原创字符串反转问题

一，第一类的字符串反转问题，也就是输入This is a string.，输出为.gnirts a si sihT，整个字符串反转：void reverse1(char *a){ int len=strlen(a)-1; int i=0; while(i<len){ char ch=a[i]; a[i++]=a[len]; a[

2015-05-02 21:27:06 426

原创 HDOJ-1002大数相加

参考这篇：点击打开链接 Problem DescriptionI have a very simple problem for you. Given two integers A and B, your job is to calculate the Sum of A + B. InputThe first line of the input contains

2015-04-26 01:08:12 400

原创栈的经典问题：括号配对

Parentheses BalanceYou are given a string consisting of parentheses() and []. A string of this type is said to be correct:(a)if it is the empty string(b)if A and B are correct,

2015-01-08 21:48:09 358

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