题解 | #单词倒排#

import java.util.*;

// 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.hasNextInt()) { // 注意 while 处理多个 case
        //     int a = in.nextInt();
        //     int b = in.nextInt();
        //     System.out.println(a + b);
        // }
        String line = in.nextLine();
        char[] clist = new char[line.length()];
        // List list = new ArrayList<>();
        int index = 0;
        for (int i = 0; i < line.length(); i++) {
            char c = line.charAt(i);
            if (c < 'A' || (c > 'Z' && c < 'a') || c > 'z') {
                c = ' ';
            }

            clist[index] = c;
            index++;
        }
        
        String s = new String(clist);
        String[] words = s.split(" ");
        for (int i = words.length - 1; i >= 0; i--) {
            String word = words[i];
            if (word == null || word.length() == 0) {
                continue;
            }
            System.out.print(word);
            
            System.out.print(" ");
        }

    }
}