【Leetcode】Implement strStr()

题目链接：https://leetcode.com/problems/implement-strstr/

题目：

Implement strStr().

Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

算法：

 public int strStr(String haystack, String needle) {
     char h[] = haystack.toCharArray();
     char n[] = needle.toCharArray();
     int i = 0, j = 0;
     while (i < h.length && j < n.length) {
         if (h[i] == n[j]) {
             j++;
             i++;
         } else {
             i = i - j + 1;
             j = 0;
         }

     }
     if (j == n.length) {
         return i - needle.length();
     } else {
         return -1;
     }
 }