#include "leetcode.h" class Solution { public: int strStr(string haystack, string needle) { int m = haystack.size(), n = needle.size(); for (int i = 0; i <= m - n; i++) { int j; for (j = 0; j < n; j++) if (haystack[i + j] != needle[j]) break; if (j == n) return i; } return -1; } }; int main() {}