GuilinDev

Lc0557

05 August 2008

557 - Reverse Words in a String III

原题概述

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

Example 1:

1
2

Input: "Let's take LeetCode contest"
Output: "s'teL ekat edoCteeL tsetnoc"

Note: In the string, each word is separated by single space and there will not be any extra space in the string.

题意和分析

只翻转字符串中每个单词的顺序，每个单词都只由一个空格隔开。用split分成一个字符串数组，然后用StringBuilder分别翻转每个单词；

如果不用StringBuilder的内置reverse方法也可以用setCharAt手动实现reverse，或者toCharArray来用数组翻转。

代码

1
2
3
4
5
6
7
8
9
10
11
12
13

class Solution {
    public String reverseWords(String s) {
        String[] words = s.split(" ");
        for (int i = 0; i < words.length; i++) {
            words[i] = new StringBuilder(words[i]).reverse().toString();//用内置方法进行翻转
        }
        StringBuilder result = new StringBuilder();
        for (String word : words) {
            result.append(word + " ");
        }
        return result.toString().trim();//去掉最后一个单词后面的空格
    }
}
This site is open source. Improve this page.