current_time
to 0 and total_waiting_time
to 0.current_time
, update current_time
to the customer's arrival time.
b. Add the customer's preparation time to current_time
to get the finish time for this customer's order.
c. Calculate the waiting time for the customer as current_time
minus the customer's arrival time.
d. Add the waiting time to total_waiting_time
.total_waiting_time
by the number of customers.