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() {
        while (stack1.size() != 0){
            stack2.push(stack1.pop());
        }
        int res = stack2.pop();
        while (stack2.size() != 0){
            stack1.push(stack2.pop());
        }
        return res;
    }
}