What kind of algorithm aptly describes the solution to this problem?
Would you want to take into account that the bottom floor will be used most often therefore at least one elevator should idle there when not in use?
A good constraint for a variable minimum N vs a variable maximum M.
Oh right, I don't think I will be able to help with this question but I think that you will need another variable for how many people use the elevators.
Assume that the floors above ground are called at random.
Separate names with a comma.