【问题描述】假设机场有一条跑道，每架飞机需花费一定时间着陆，花费一定时间起飞，飞机的起降满足一定的概率。一般来讲，机场存在两个队列，一个等待着陆的飞机队列和一个等待起飞的飞机队列，同样等待时间下，等待着陆的飞机比准备起飞的飞机具有更高的优先级。试编写程序模拟这个机场的运行。

【基本要求】使用队列或优先队列实现；要求可以变换起飞和着陆频率来模拟一天中的飞行高峰期和空闲期；要求可以改变着陆和起飞时间以模拟不同的效果。

【实现提示】可以假设有一个每次前进一分钟的模拟时钟，对于每一分钟，产生两个随机数：如果第一个随机数小于landingRate/60，那么一个“着陆到达”将发生并被添加到着陆队列中；如果第二个随机数小于takeOffRate/60，那么一个“起飞到达”将发生并被添加到起飞队列中。接着，检查跑道是否空闲。若空闲，首先检查着陆队列是否为非空，如果是，允许第一架飞机着陆；否则，处理起飞队列。

-Descr iption of the problem the assumption that the airport has one runway, each aircraft landing takes a certain period of time, take some time to take off, taking off and landing of aircraft to meet a certain probability. Generally speaking, the airport there are two queues, a queue waiting for the aircraft landing, and a waiting for takeoff the aircraft queue, the same wait time, waiting for the landing of the aircraft has a higher priority than the aircraft ready to take off. Try to write a program to simulate the operation of the airport.

Requirements】 queue or priority queue implementation　requirements can transform the frequency of take-off and landing day to simulate the flight peak periods and the idle period　requirements can change the landing and take-off time in order to simulate different effects.

[Tip] can be assumed to have an analog clock forward one minute at a time, every minute, resulting in two random numbers: If the first random number is less than landingRate/6