Implement strStr().
Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack.
This is a simple problem,
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public class Solution { public
String strStr(String haystack, String needle) { int
hlen = haystack.length(), nlen = needle.length(); String result = null; if(nlen <= hlen){ if(nlen == 0) result = haystack; else{ for(int
i = 0; i < hlen - nlen + 1; ++i){ int
j = 0; for(; j < nlen; ++j){ if(haystack.charAt(i) == needle.charAt(j)) ++i; else break; } i = i - j; //we found the first needle if(j == nlen){ result = haystack.substring(i, hlen); break; } } } } return
result; }} |
原文：http://www.cnblogs.com/averillzheng/p/3564465.html