Hi everybody!

Recently I've learned hungarian algorithm for solving the assignment problem, Now I'm curious about how to solve more general problem: for given n × m table select several numbers, maximizing their sum with following constraints: in each row the number of selected numbers is not less than R_min and not more than R_max, and for each column the number of selected numbers is not less than C_min and not more than C_max.

If R_min = R_max = 1 and C_min = C_max = 1 this is the standard assignment problem. But what can we say about more general case? Any ideas about this (maybe, at least in case R_min = R_max = R, C_min = C_max = C)? Any thoughts would be greatly appreciated.