Write a program that simulates a checkout line at a supermarket. The line is a queue object. Customers( i.e customer objects) arrive in random integer intervals of 1-4 minutes. Also each customer is served in random integer intervals of 1-4 minutes. Obviously, the rates need to be balanced. If the average arrival rate is larger than the average service rate, the queue will grow infinitely. Even with " Balanced" rates, randomness can still cause long lines. Run the supermarket simulation for a 12 hour day(720 minutes) using the following algorithm:
1) choose a random integer between 1 and 4 to determine the minute at which the first customer arrives.
2) At the first customer's arrival time: 
Determine customer's service time (random integer from 1 to 4);
Begin servicing the customer;
Schedule arrival time of next customer (random integer 1 to 4 added to the current time).
3) For each minute of the day;
If the next customer arrives, 
Say so, 
Enqueue the customer;
Schedule the arrival time of the next customer;
If service was completed for the last customer;
Say so
Dequeue next customer to be serviced
Determine customer's service completion time( random integer from 1 to 4 added to the current time).
Now run your simulation for 720 minutes and answer each of the following: 
a) What's the maximum number of customers in the queue at any time?
b) What's the longest wait any one customer experiences?
c) What happens if the arrival interval is changed from 1-4 minutes to 1-3 minutes?