Implement strStr()

Implement strStr().
Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack.

Solution: Brute force method: check in the haystack one by one. If not equal to needle, reset the pointer.
More solutions can be referred as http://leetcode.com/2010/10/implement-strstr-to-find-substring-in.html
Advanced algorithms such as KMP can be also found via the above link

class Solution {
public:
    char *strStr(char *haystack, char *needle) {
        while(1) {
            char* h = haystack, *n = needle;
            while(*n != '' && *h == *n) {
                h++; n++;
            }
            if(*n == '') return haystack;
            if(*h == '') return NULL;
            haystack++;
        }
    }
};