#106

Number Maze

 

Given a pair of numbers, the start and end point, find a path between the two using only three possible operations:

• double
• halve (odd numbers cannot be halved)
• add 2

Find the shortest path through the "maze". Because there are multiple shortest paths, you must return the length of the shortest path, not the path itself.

	(= 1 (__ 1 1)) ; 1
	(= 3 (__ 3 12)) ; 3 6 12
	(= 3 (__ 12 3)) ; 12 6 3
	(= 3 (__ 5 9)) ; 5 7 9
	(= 9 (__ 9 2)) ; 9 18 20 10 12 6 8 4 2
	(= 5 (__ 9 12)) ; 9 11 22 24 12