You are in a supermarket with only self-checkout counters. Write a function to calculate the total time needed for all the customers to check out.
The function signature is as such:
computeQueueTime(customers, n)customers: An array of positive integers. Each integer represents a customer, and its value is how long they require to check out.n: The number of self-checkout counters in the supermarket.
Here are some examples:
computeQueueTime([5,3,4], 1)
- should return 12
- because when n=1, the total time is just the sum of the times
computeQueueTime([10,2,3,3], 2)
- should return 10
- because here n=2 and the 2nd, 3rd, and 4th people in the
- queue finish before the 1st person has finished.
computeQueueTime([2,3,10], 2)
- should return 12
You can assume the following:
- There is only a single queue to use the counters.
- The order of the queue will never change.
- The person at the front of the queue proceeds to a counter as soon as it becomes free with no lag time.
Management is thinking to re-introduce some traditional staffed counters to facilitate faster checking out of customers who are less conversant with self-checkout.
These trained staff will be able to serve a customer twice as fast as a self-checkout counter.
Modify your function to incorporate a second type of counter. You should be able to use this function to advice management exactly how much faster the checkouts will be. The new function signature should be:
computeQueueTime(customers, n, m)
m(new): The number of traditional staffed counters that perform checkouts twice as fast as self-checkout counters.
Note:
- There is still only 1 queue to access all counters, regardless of the type of counter.
- Assume all customers are still the same and are not split by how conversant they are with self-checkout. The first person in the queue continues to use whichever counter is available.
- This was adapted from a kata on Codewars.
- The supermarket queue is analogous to the thread pool in computer science.
- Concept of concurrency in computer science.