Reverse Words in a String 翻转一个字符串里的单词顺序 @LeetCode

LeetCode字符串翻转题解析

最新推荐文章于 2022-11-23 17:07:59 发布

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本文介绍了一道LeetCode上的简单题目：按单词翻转字符串。通过使用栈来实现字符串中每个单词的逆序输出，并保留单词间的单个空格。文章提供了完整的Java代码示例。

LeetCode新题，但是比较简单，直接用栈即可

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.

Clarification:

What constitutes a word?
A sequence of non-space characters constitutes a word.
Could the input string contain leading or trailing spaces?
Yes. However, your reversed string should not contain leading or trailing spaces.
How about multiple spaces between two words?
Reduce them to a single space in the reversed string.

public class Solution {
    public String reverseWords(String s) {
        if(s.length() == 0) {
            return s;
        }
        Stack<String> stack = new Stack<String>();
        String[] ss = s.split("\\s+");
        for(String word : ss) {
            stack.push(word);
        }
        StringBuilder sb = new StringBuilder();
        while(!stack.isEmpty()) {
            sb.append(stack.pop()).append(" ");
        }
        return sb.toString().trim();
    }
}