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 scanner = new Scanner(System.in);
        scanner.useDelimiter("\n");

        String s1 = null;
        Stack<String> stack = new Stack<>();
        while (scanner.hasNext()) {
            s1 = scanner.next();
            if (s1 == null || s1.length() == 0) continue;
            for (String s : s1.split("[^a-z_A-Z]+")) {
                stack.push(s);
            }
            while (!stack.isEmpty()) {
                System.out.print(stack.pop()+" ");
            }
        }
    }
}