用两个栈实现一个队列

package 栈与队列上;

import java.util.Stack;

public class MyQueue {
	public Stack stack1 = new Stack();
	public Stack stack2 = new Stack();
	public int size;

	public void push(int x) {
		stack1.push(x);
		size++;
	}

	public void pop() {
		if (!stack2.isEmpty()) {
			stack2.pop();
		} else {
			while (!stack1.isEmpty()) {
				stack2.push(stack1.pop());
			}
			stack2.pop();
		}
		size--;
	}

	public int peek() {
		if (!stack2.isEmpty()) {
			return stack2.peek();
		} else {
			while (!stack1.isEmpty()) {
				stack2.push(stack1.pop());
			}
			return stack2.peek();
		}
	}

	public boolean empty() {
		return size == 0 ? true : false;
	}

	public static void main(String[] args) {
		MyQueue myqueue = new MyQueue();
		System.out.println("队列初始大小：" + myqueue.size);
		myqueue.push(1);
		myqueue.push(2);
		myqueue.push(3);
		System.out.println("队列赋值后大小：" + myqueue.size);
		while (!myqueue.empty()) {
			System.out.print(myqueue.peek() + " ");
			myqueue.pop();
		}
	}
}