leetcode JAVA Reverse Words in a String 难度系数2-3？最新题151

昨天睡觉之前，同学提醒说leetcode出了道新题，早上爬起来做了一下，本来用了string的split,写完发现二了，没有办法切割多个空格的情况，如果想切割多个空格，那就一定要带上正则表达式了。于是老老实实的从尾遍历到头。

好吧，上代码：

Reverse Words in a String

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

click to show clarification.

public class Solution {
    public String reverseWords(String s) {
        if(s==null)
        	return "";
        s = s.trim();
        if(s=="")
        	return "";
        StringBuffer sb = new StringBuffer();
        int i = s.length()-1;
        int last = i;
        while(i>=0){
        	while(i>=0&&s.charAt(i)!=‘ ‘){
        		i--;
        	}
        	String temp = s.substring(i+1,last+1);
        	sb.append(temp);
        	sb.append(" ");
        	while(i>=0&&s.charAt(i)==‘ ‘){
        		i--;
        	}
        	last = i;
        }
        while(sb.length()>1&&sb.charAt(sb.length()-1)==‘ ‘)
        	sb.deleteCharAt(sb.length()-1);
        return sb.toString();
    }
}

leetcode JAVA Reverse Words in a String 难度系数2-3？最新题151,布布扣,bubuko.com

leetcode JAVA Reverse Words in a String 难度系数2-3？最新题151

原文：http://blog.csdn.net/yiding_he/article/details/20741155