题解 | #单词倒排#

import java.util.*;
import java.lang.*;


// 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()) { // 注意 while 处理多个 case
            String a = in.nextLine();
            StringBuilder  strn = new StringBuilder();
            for (int i = 0; i < a.length(); i++) {
                if (!Character.isLetter( a.charAt(i))) {
                    strn.append(" ");
                } else {
                    strn.append(a.charAt(i));
                }
            }

            String[] key = strn.toString().split(" ");
            List<String> result = Arrays.asList(key);
            Collections.reverse(result);
            for (String s : result) {
                System.out.print(s + " ");
            }
        }
    }
}