Pentalpha is a puzzle where the goal is to place nine stones on the ten intersections of a pentagram. The puzzle is used as a confidence trick in Mexico, where it is known as estrella mágica.John Fisher, Never Give a Sucker an Even Break The following rules need to be obeyed when placing the stones: The stone has to visit two other points before reaching its final point. These three points have to be next to each other. The points have to be in a straight line. Although the second (middle) point is allowed to be occupied by a stone, the first (starting) and third (ending) points must be clear before a stone is placed at the third (ending) point.
Solution The solution to Pentalpha can be found for any starting point using the following algorithm: Choose a node X. Travel two nodes in a straight line to node Y. From node Y, place a stone at node X. Let node Y be the new node X. Repeat step 2-4 until the puzzle is solved.
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