逆序输出字符串的单词——Leetcode系列（二）

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

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

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.

My Answer:

public class Solution {
    public String reverseWords(String s) {
        String[] array = s.split(" ");
        StringBuilder builder = new StringBuilder();
        String space = " ";
        int length = array.length - 1;
        for(int i = length; i >= 0; i--){
            String cleanStr = array[i].trim();
            if(cleanStr.length() == 0){
                continue;
            }
            
            builder.append(cleanStr);
            builder.append(space);
        }
        return builder.toString().trim();
    }
}

题目来源：https://oj.leetcode.com/problems/reverse-words-in-a-string/