题目：28. 找出字符串中第一个匹配项的下标

思路

观察法（呵呵呵）

代码

class Solution {
public:int strStr(string haystack, string needle) {if(needle.empty()){return 0;}int i, j = 0, x1, x2;for(i = 0; i < haystack.size(); i++){if(haystack[i] == needle[0]){for(j = 1; j < needle.size(); j++){if(haystack[i+j] != needle[j]){break;}}if(j == needle.size()){return i;}}}return -1;}
};