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

        String str = in.nextLine();
        StringBuilder sb = new StringBuilder();
        //处理字符串，去除特殊字符，保留空格
        char[] ch = str.toCharArray();
        for (int i = 0; i < ch.length; i++) {
            if (ch[i] >= 'a' && ch[i] <= 'z') {
                sb.append(String.valueOf((char)ch[i]));
            } else if (ch[i] >= 'A' && ch[i] <= 'Z') {
                sb.append(String.valueOf((char)ch[i]));
            } else {
                sb.append(" ");
            }
        }
        String[] temp = sb.toString().split(" ");
        for(int i = temp.length - 1;i >=0;i--){
            System.out.print(temp[i] + " ");
        }
    }
}