剑指Offer_05_用两个栈实现队列

题目描述

解题思路

实现

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 (stack1.isEmpty() && stack2.isEmpty()) return -1;
if (stack2.isEmpty()){
while (!stack1.isEmpty()){
stack2.push(stack1.pop());
}
}
return stack2.pop();
}
}