c_cpp 28.实施strStr- DifficultyEasy - 2018.8.25

Posted 2021-05-14

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