题解 | #用两个栈实现队列#

import java.util.Stack;

public class Solution {
    Stack<Integer> stack1 = new Stack<Integer>();
    Stack<Integer> stack2 = new Stack<Integer>();
    
    public void push(int node) {
        stack1.push(node);
    }
    
    public int pop() {
            if(!stack2.empty()){
                System.out.println("test not:"+stack2.peek());
                return stack2.pop();
            }else{
                while(true){
                    if(!stack1.empty()){
                        stack2.push(stack1.pop());
                    }else{
                        break;
                    };
                }
        
                if(!stack2.empty()){
                    return stack2.pop();
                }
                
            }
            return 0;
    }
}