3 ms·The Fifteen Puzzle3 points by phleet 15y agopmiller2 15y agoSolution via group theory: http://www.cs.cmu.edu/afs/cs/academic/class/15859-f01/www/notes/15-puzzle.pdf http://www.cs.cmu.edu/afs/cs/academic/class/15859-f01/www/no...