LeetCode Implement strStr

Description

The original problem is here.

The original code is here.

My Solution

I solve this problem in C++, as below:

/*
*Implement strStr()  
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<stdlib.h>
using namespace std;

class Solution {
public:
    int strStr(string haystack, string needle) {
        int i, j;
        for (i = j = 0; i < haystack.size() && j < needle.size();) {
            if (haystack[i] == needle[j]){
                ++i; ++j;
            }
            else{
                i -= j - 1; j = 0;
            }
        }
        return j != needle.size() ? -1 : i - j;
    }
};

Note

Traversal the haystack, and find whether the substring is match to needle.