电梯模拟程序，里面有6个类分别实现电梯运行中的上下乘客，上下行方向，乘客坐电梯的概率，电梯内按钮等，还能把统计数据保存到数据库。-Elevator simulation program, which has six categories, respectively, to achieve in the operation of the elevator up and down passengers, up and down direction, the probability of passen