class Solution {
public:
int strStr(string haystack, string needle) {
int j = 0; //标记needle的初始位置
int h = haystack.length(), n = needle.length();
if (!n) {
return 0;
}
for (int i =0; i<h-n+1; i++) {
int tmp = i;
while (tmp<h && j<n && haystack[tmp]==needle[j]) {
tmp++;
j++;
}
if (j==n) {
return i;
}else{
j=0;
}
}
return -1;
}
};
