1040. Moving Stones Until Consecutive II

There are some stones in different positions on the X-axis. You are given an integer array stones, the positions of the stones. Call a stone an endpoint stone if it has the smallest or largest position. In one move, you pick up an endpoint stone and move it to an unoccupied position so that it is no longer an endpoint stone. - In particular, if the stones are at say, stones = [1,2,5], you cannot