zoukankan      html  css  js  c++  java
  • Java [leetcode 28]Implement strStr()

    题目描述:

    Implement strStr().

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

    Update (2014-11-02):
    The signature of the function had been updated to return the index instead of the pointer. If you still see your function signature returns a char * or String, please click the reload button to reset your code definition.

    解题思路:

    从开头开始,逐个匹配。

    注意特殊情况。

    代码如下:

    public class Solution {
        public static int strStr(String haystack, String needle) {
    		int haystackLength = haystack.length();
    		int needleLength = needle.length();
    		int j = 1;
    		if (needleLength == 0)
    			return 0;
    		if (needleLength > haystackLength)
    			return -1;
    		for (int i = 0; i <= haystackLength - needleLength; i++) {
    			if (haystack.charAt(i) == needle.charAt(0)) {
    				for (j = 1; j < needleLength; j++) {
    					if (haystack.charAt(i + j) != needle.charAt(j))
    						break;
    				}
    				if (j == needleLength)
    					return i;
    			}
    		}
    		return -1;
    	}
    }
    
  • 相关阅读:
    Win10中的IIS10安装php manager和IIS URL Rewrite
    第十四周
    第十三周
    第十二周
    第十一周
    第十周
    第九周
    测试作业
    第八周
    第七周
  • 原文地址:https://www.cnblogs.com/zihaowang/p/4507462.html
Copyright © 2011-2022 走看看