题解 | #单词倒排#

import java.util.Arrays;
import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while(in.hasNextLine()){
            String s = in.nextLine();
            int n = s.length();
            StringBuilder sb = new StringBuilder("");
            for(int i=0 ; i<n ; ++i){
                char c = s.charAt(i);
                c = Character.toLowerCase(c);
                if(!(c>='a' && c<='z')){
                    sb.append(" ");
                }
                else{
                    sb.append(s.charAt(i));
                }
            }

            String[] words = sb.toString().split(" ");
            sb = new StringBuilder("");
            for(int i=words.length-1 ; i>=0 ; --i){
                if(!words[i].equals("")){
                    sb.append(words[i]+" ");
                }
            }
            System.out.println(sb.toString());
        }
    }
}