<quote>we have to plus?
Actually we have to subtract: Steps = Max - Min
In case Min is less than zero, this evolves in a doulbe-minus if we write the actual numbers down. But you don't have to worry about that if you leave the computation to a machine. Just tell it to "Max - Min" and it will take care of the sign on its own.
Question was for the step count. Number of possible positions is (stepCount + 1).
I am not confusing anyone. It depends (forgive me if I am not using proper terminology) of range. Is this closed? Opened? From both or from one side? For example range <-1,1> have 3 integers. Range <-1,1) have 2 ints. (-1,1> have 2 too. But (1,1) have only 0. Your substraction is range (-10000,-10000>. For me in this case you should either take closed from or opened from both range. But question is not clear about that som I can be wrong.