题解 | 交换变量值

import java.util.Scanner; 

import java.util.Stack;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();

        //write your code here.......
        Stack<Integer> stack=new Stack<>();
        stack.push(a);
        stack.push(b);
        if(!stack.isEmpty()){
            a=stack.pop();
        }
        if(!stack.isEmpty()){
            b=stack.pop();
        }


        System.out.println(a+" "+b);
    }
}

用了栈