Implement strStr().
Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
分析：
给出两个字符串，查询第二个字符串是否在第一个字符串中出现过，如果有，就返回第一次出现的位置。
If source = "source" and target = "target", return -1.
If source = "abcdabcdefg" and target = "bcd", return 1.
public class Solution { public int strStr(String haystack, String needle) { if (haystack == null || needle == null){ return -1; } for (int i = 0; i < haystack.length() - needle.length() + 1; i++){ int j = 0; for (j = 0; j < needle.length(); j++){ if (haystack.charAt(i + j) != needle.charAt(j)){ break; } } if (j == needle.length()){ return i; } } return -1; } }
leetcode 28. Implement strStr()
原文：http://www.cnblogs.com/iwangzheng/p/5742544.html