停车场

代码说明：

说明：  模拟停车场，可实现功能为：1.记录停车时间并计算停车费 2.智能计算停车位空余，用栈的方法进行排序 3.可查看停车场状态(The functions of the simulated parking lot are as follows: 1. Record the parking time and calculate the parking fee; 2. Intelligently calculate the parking space vacancy and sort it with the method of stack; 3. Check the status of the parking lot)