用两个栈来实现一个队列

题目描述

import java.util.Stack;

public class Solution {
Stack<Integer> stack1 = new Stack<Integer>();
Stack<Integer> stack2 = new Stack<Integer>();

public void push(int node) {
while(!stack2.isEmpty()) {
Integer pop = stack2.pop();
stack1.push(pop);
}
stack1.push(node);
}

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