Reverse Words in a String

翻转字符串里的单词

题目

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

Example:

Input: “the sky is blue”,
Output: “blue is sky the”.
Note:

A word is defined as a sequence of non-space characters.
Input string may contain leading or trailing spaces. However, your reversed string should not contain leading or trailing spaces.
You need to reduce multiple spaces between two words to a single space in the reversed string.
Follow up: For C programmers, try to solve it in-place in O(1) space.

解析重点

1.先出除多余的空格，然后根据空格切分字符串，将切分后的字符串数组翻转，然后连接即可。

java代码

public class Solution {
    public String reverseWords(String s) {
    String[] words = s.trim().split(" +");
    Collections.reverse(Arrays.asList(words));
    return String.join(" ", words);
}
}