Implement strStr().
Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
解题思路：
直接看代码即可，JAVA实现如下：
static public int strStr(String haystack, String needle) {
for(int i=0;i<=haystack.length()-needle.length();i++)
if(haystack.substring(i, i+needle.length()).equals(needle))
return i;
return -1;
}
Java for LeetCode 028 Implement strStr()
原文：http://www.cnblogs.com/tonyluis/p/4474658.html