Pentalpha

Pentalpha is a puzzle where the goal is to place nine stones on the ten intersections of a pentagram. The following rules need to be obeyed when placing the stones:

1. The stone has to visit two other points before reaching its final point.
2. These three points have to be next to each other.
3. The points have to be in a straight line.
4. The first and third (final) points are not allowed to be occupied, the second point is.

Solution

The solution to Pentalpha can be found for any starting point using the following algorithm:

1. Choose a node X.
2. Travel two nodes in a straight line to node Y.
3. From node Y, place a stone at node X.
4. Let node Y be the new node X.
5. Repeat step 2-4 until the puzzle is solved.
6. Congratulations for completing it.