1701. Average Waiting Time

There is a restaurant with a single chef. You are given an array customers, where customers[i] = [arrivali, timei]: - arrivali is the arrival time of the ith customer. The arrival times are sorted in non-decreasing order. - timei is the time needed to prepare the order of the ith customer. When a customer arrives, he gives the chef his order, and the chef starts preparing it once he is idle. Th