Custom cost function incorporation

[armantigranyan]

Hello and thank you for the solution! I am using it to solve a mix of Set Cover and TSP, and I was wondering if it's possible to use your solution to work with a more flexible cost function. More specifically, I have an array of costs for each set and eventually want to minimize total_cost/num_of_sets_selected. It seems to me that the current version tries to minimize the sum of the costs of the selected sets. Thank you!