A server has n customers waiting to be served. The service time required by each customer...

A server has n customers waiting to be served. The service time required by each customer is known in advance: it is ti minutes for customer i. So if, for example, the customers are served in order of increasing i, then the ith customer has to wait  minutes.

We wish to minimize the total waiting time

Give an efficient algorithm for computing the optimal order in which to process the customers.