class Solution {
public:
int strStr(string haystack, string needle) {
int len_h = haystack.length();
int len_n = needle.length();
if(len_n == 0)
return 0;
if(len_h < len_n)
return -1;
for(int i = 0; i <= len_h-len_n; ++i){
if(!(haystack.compare(i, len_n, needle)))
return i;
}
return -1;
}
};
需要比较两个字符串的长度