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) {
        // 入栈数据时，将入栈的数据放在stack1中，然后将stack1中的数依次出栈压入stack2中
        stack1.push(node);

    }

    public int pop() {
        while (!stack1.empty()) {
            stack2.push(stack1.pop());
        }
        int temp = stack2.pop();
        while (!stack2.empty())
        {
            stack1.push(stack2.pop());
        }
        return temp;
    }
}