题解 | #单词倒排#

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
        StringBuilder s = new StringBuilder();
        int ci = 0;//标记连续空格用
        while(in.hasNext()){
            String ssss = in.next();
            for(int i=0; i<ssss.length(); i++){
                if(Character.isLetter(ssss.charAt(i))){
                    s.append(ssss.charAt(i));
                    ci = 1;
                }else if(!Character.isLetter(ssss.charAt(i)) && ci == 1){
                    s.append(" ");
                    ci = 0;
                }
            }
            s.append(" ");
        }
        String[] ss = s.toString().split(" ");
        int len = ss.length;
        for(int i=len-1; i>=0; i--){
            System.out.print(ss[i] + " ");
        }
    }
}