Introduction - If you have any usage issues, please Google them yourself
There is a long and narrow parking lot for n cars. It has only one gate to get in and out of the car. Vehicles are parked from the inside of the parking lot to the gate at the end of the parking lot (the first car first arrives at the bottom of the parking lot). If the parking lot is full of N cars, the later vehicle can only wait on the sidewalk outside the parking lot gate. Once the car is opened, the first car on the sidewalk will enter the parking lot. If a car wants to leave in the parking lot, after he enters the parking lot, the car must exit the parking lot to make way for it. After the parking lot is opened, the vehicles will enter the original order.