Leetcode 28. Implement strStr()

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

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http://noahsnail.com/images/leetcode/Implement_strStr().jpeg

2. Solution

• Version 1

class Solution {
public:
    int strStr(string haystack, string needle) {
        if(needle.length() == 0) {
           return 0; 
        }
        for(int i= 0; i < haystack.length(); i++) {
            bool flag = true;
            if(haystack[i] == needle[0]) {
                for(int j = 1; j < needle.length(); j++) {
                    if(haystack[i + j] != needle[j]) {
                        flag = false;
                        break;
                    }
                }
                if(flag) {
                    return i;
                }
            }
        }
        return -1;
    }
};

• Version 2

Reference

1. https://leetcode.com/problems/implement-strstr/description/