Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 注:直接看题目可能会有些偏差,因为容易认为 needle是一个字符,那就也太容易了,实则,haystack和needle都是字符串(注意是字符串不是数组) 解法思路: 暴力搜索: public class Solution { public int…

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();…

# -*- 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…

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-…

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…

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…

Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Solution:  class Solution { public: int strStr(string haystack, string needle) { //runtime:4ms int len1=haystack.size(), len…

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(). 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",…

28.Implement strStr() 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…

这是悦乐书的第151次更新,第153篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第10题(顺位题号是28).给定两个任意字符串haystack.needle,返回haystack中第一次出现needle的索引,如果needle不是haystack的一部分,则返回-1.如果needle为空串,则返回0.例如: 输入:haystack ="hello",needle ="ll" 输出:2 输入:haystack ="aaaaa&…

因为最近一段时间接触了一些Leetcode上的题目,发现许多题目的解题思路相似,从中其实可以了解某类算法的一些应用场景. 这个随笔系列就是我尝试的分析总结,希望也能给大家一些启发. 动态规划的基本概念 一言以蔽之,动态规划就是将大问题分成小问题,以迭代的方式求解. 可以使用动态规划求解的问题一般有如下的两个特征: 1.有最优子结构(optimal substructure) 即待解决问题的最优解能够通过求解子问题的最优解得到. 2.子问题间有重叠(overlapping subproplems)…

Leetcode里面关于字符串的一些问题,描述如下: Given an input string, reverse the string word by word. For example,Given s = "the sky is blue",return "blue is sky the". Update (2015-02-12):For C programmers: Try to solve it inO(1) space. click to show cla…

1.题目描述 2.题目分析 字符串操作,注意边界条件即可. 3.代码 int strStr(string haystack, string needle) { int n = needle.size(); ; ) ; for(string::iterator it = haystack.begin() ; it != haystack.end(); ++it){ ]){ bool isEqual = true; bool isEnd = false; ; i < n; i++){ if( it…

问题描述: 在股市的交易日中,假设最多可进行两次买卖(即买和卖的次数均小于等于2),规则是必须一笔成交后进行另一笔(即买-卖-买-卖的顺序进行).给出一天中的股票变化序列,请写一个程序计算一天可以获得的最大收益.请采用实践复杂度低的方法实现. 给定价格序列prices及它的长度n,请返回最大收益.保证长度小于等于500. class Solution { public: int maxProfit(vector<int>& prices) { //It's wrong if you c…

Question: Find the contiguous subarray within an array (containing at least one number) that has the largest sum. For example, given the array [2, 1, –3, 4, –1, 2, 1, –5, 4], The contiguous array [4, –1, 2, 1] has the largest sum = 6. 此问题提供了两种解决方案,首先…

Given a string, find the length of the longest substring without repeating characters. Examples: Given "abcabcbb", the answer is "abc", which the length is 3. Given "bbbbb", the answer is "b", with the length of 1.…

Validate if a given string is numeric. Some examples:"0" => true" 0.1 " => true"abc" => false"1 a" => false"2e10" => true 解决方案: public class Solution { public boolean isNumber(String s) { in…

Question: 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" is not a palindrome.Example Questions C…

class Solution { public: vector<pair<int, int>> getSkyline(vector<vector<int>>& buildings) { vector<pair<int, int> > h, res; multiset<int> m; , cur = ; for (auto &a : buildings) { h.push_back({a[], -a[]});…

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…

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…

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…

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…

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",…

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(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 思路: 注意,在for循环中条件有计算得到的负数时, 一定要把计算括起来转换为int, 否则会默认转换为uchar 负数就会被误认为是一个很大的数字. ; i < - ); ++i) 实现很常规: int strStr(string haystac…

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…

Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. Summary: be careful about the corner case, haystack = "", needle = "" char *strStr(char *haystack, char *ne…