设停车场是一个可以停放n辆汽车的狭长通道，且只有一个大门可供汽车进出。汽车在停车场内按车辆到达时间的先后顺序，依次有北向南排列（大门在最南端，最先到达的第一车停放在车场的最北端），若车场内已停满n辆车，那么后来的车只能在门外的便道上等候，一旦有车开走，则排在便道上的第一辆车即可开入；当停车场内某辆车要离开时，-Car parks are located a vehicle parked n the long and narrow channel, and there is only one door open to motor out. Car in the parking lot with the arrival of the vehicles by the time the order are arranged north to south (the southern tip of the door in the first car to reach the first car parked in the most northern end), if the car had been parked inside vehicles over n, then later vehicles can only wait for the sidewalk outside, once the car away, then in the sidewalk on the first car to be opened　when parking vehicles within a certain time to leave,