LeetCode解题之Implement strStr() 原题 实现字符串子串匹配函数strStr(). 假设字符串A是字符串B的子串.则返回A在B中首次出现的地址.否则返回-1. 注意点: - 空字符串是全部字符串的子串,返回0 样例: 输入: haystack = "abc", needle = "bc" 输出: 1 输入: haystack = "abc", needle = "gd" 输出: -1 解题思路 字符串匹…

Github leetcode 我的解题仓库   https://github.com/interviewcoder/leetcode 题目: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02):The signature of the function ha…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02): The signature of the function had been updated to return the index instead of the pointer. If you still…

[题目] Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. [题意] 实现库函数strStr(), 功能是在字符串haystack中找出目标串needle第一次出现的索引位 [思路] 字符串的匹配,能够用暴力解法,但不推荐.一般使用KMP算法求解. 简要介绍一下KMP的思想: haystack…

Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. 这个题考查的是KMP算法.先求特征向量,然后再进行匹配,确实能够大大提高效率.code例如以下: class Solution { public: char *strStr(char *haystack, char *needle) { if(…

Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. I wrote that function before in practice without knowing anything about strStr(), so I have a pretty clear brute-force sol…

#kmp class Solution(object): def strStr(self, haystack, needle): """ :type haystack: str :type needle: str :rtype: int """ if len(haystack) <= 0 and len(needle)<=0: return 0 arrNext=self.getNext(needle) i=0 j=0 intHLen=…

如题 思路:暴力就行了.1ms的暴力!!!别的牛人写出来的,我学而抄之~ int strStr(char* haystack, char* needle) { ; ; ; ++i) { ; ; ++j) { ) return i; ) ; if (haystack[i + j] != needle[j]) break; } } } strStr()…

https://leetcode.com/problems/implement-strstr/  28. Implement strStr() 暴力算法: int ViolentMatch(char* s, char* p) { int sLen = strlen(s); int pLen = strlen(p); ; ; while (i < sLen && j < pLen) { if (s[i] == p[j]) { //①如果当前字符匹配成功(即S[i] == P[j]…

# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 28: Implement strStr()https://oj.leetcode.com/problems/implement-strstr/ Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of h…

爱写bug(ID:icodebugs) 作者:爱写bug 实现 strStr() 函数. 给定一个 haystack 字符串和一个 needle 字符串,在 haystack 字符串中找出 needle 字符串出现的第一个位置 (从0开始).如果不存在,则返回 -1. Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of…

1 题目: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02):The signature of the function had been updated to return the index instead of the pointer. If you…

Brute Force算法,时间复杂度 O(mn) def strStr(haystack, needle): m = len(haystack) n = len(needle) if n == 0: return 0 if m < n: return -1 for i in range(m - n - 1): for j in range(n): if haystack[i + j] != needle[j]: break elif j == n - 1: return i return -1…

Implement strStr() Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. MY: Question. 思路: 逐步查找.当出现不同时,如何回溯是关键. Solution A: class Solution { public: char *strStr(char *haystack…

Implement strStr() Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 最简单的思路,逐一比较: class Solution { public: int strStr(char *haystack, char *needle) { int n1=strlen(haystack);…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 解题思路一: 暴力枚举,JAVA实现如下: static public int strStr(String haystack, String needle) { for(int i=0;i<=haystack.length()-needle.len…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 问题:实现 strStr() 函数.即在  haystack 中匹配 needle 字符串. 可以理解为,实际上这道题是在问如何实现 KMP(Knuth–Morris–Pratt) 算法.这是个效率比较高的算法,只需要扫一遍 haystack 就可…

Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. 就是判断haystack中是否有needle,如果包含的话,返回第一次包含的地址.如果没有则返回NULL. 这题官网打出来的是easy,但是要做好绝不简单.我能想到的就是O(m*n)的复杂度了.最经典的是用KMP算法. class Soluti…

一天一道LeetCode系列 (一)题目 Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. (二)解题 第一种解法:朴素匹配算法 /* 两个指针,分别指向两个字符串的首字符 如果相等则一起向后移动,如果不同i取第一个相同字符的下一个开始继续匹配 如果最后j等于needle的长度则匹配成功,返回i-…

导航页-LeetCode专题-Python实现 相关代码已经上传到github:https://github.com/exploitht/leetcode-python 文中代码为了不动官网提供的初始几行代码内容,有一些不规范的地方,比如函数名大小写问题等等:更合理的代码实现参考我的github repo 1.读题 Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1…

题目: Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. 题解: 其实我觉得这题..为啥不给个更明确的解释呢? 是不是如果不知道strStr()是干嘛的就给直接挂了呢... 这道题就是让你判断,needle是不是haystack的子串,是的话就返回这个子串. 解题想法是,从haystack的第…

Implement strStr() Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. 解法一:暴力解 class Solution { public: int strStr(string haystack, string needle) { int m = haystack.size();…

这个题目是典型的KMP算法,当然也可以试试BM,当然有关KMP和BM的介绍阮一峰曾经写过比较好的科普,然后july也有讲解,不过那个太长了. 先放题目吧: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02): The signature of the func…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 额,当然我用的就是暴力搜索来,没用到KMP之类的算法,有时间再来补上辣,代码如下: class Solution { public: int strStr(string haystack, string needle) { ; ; ; i <= h…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 解题: 本题为典型的KMP算法考察题,KMP算法描述为: 设主串S,匹配串P,i为S的索引下标,j为P的索引下标,初始i和j设置为0. 在i小于S的长度和j小于P的长度时,开始循环: 1.比较S[i]和P[j]是否相同: 2.如果相同则i++,j+…

题目 Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Update (2014-11-02): The signature of the function had been updated to return the index instead of the pointer. If you st…

https://leetcode.com/problems/implement-strstr/ 题目: Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 思路: 判断一个string是否另一个string的子序列并返回位置. naive法:遍历查找,复杂度O(mn). advance法还有Rabi…

Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Example 1: Input: haystack = "hello", needle = "ll" Output: 2 Example 2: Input: haystack = "aaaaa",…

问题 该文章的最新版本已迁移至个人博客[比特飞],单击链接 https://www.byteflying.com/archives/3895 访问. 实现 strStr() 函数. 给定一个 haystack 字符串和一个 needle 字符串,在 haystack 字符串中找出 needle 字符串出现的第一个位置 (从0开始).如果不存在,则返回  -1. 输入: haystack = "hello", needle = "ll" 输出: 2 输入: hayst…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 find函数 遍历+切片 日期 题目地址:https://leetcode.com/problems/implement-strstr/description/ 题目描述 Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1…