Dear sir, I have a query on robotic movement could u please help me out in solving it ??

Query is :-

A robot has to define to pick and place 2 different kind of balls in the shelf which is linear in nature and when picking up it has to follow the rule as left & right side of the ball should not be of same kind and the robot has to give solution as how many balls are there of each kind and while placing it has to utilize the complete set of available space then only it can say you have no space to place the ball.!

I will be highly thankful to you if u could give some good solution on this!

Waiting for your reply!Hope to listen from you ASAP