Can anyone suggest how to solve the Log Pile wooden puzzle using a computer program?
See here to visualise the puzzle: http://www.puzzlethis.co.uk/products/madcow/the_log_pile.htm
The picture only shows some of the pieces. The full set of 10 pieces are configured as follows with 1 representing a peg, -1 representing a hole and 0 representing neither a peg nor a hole.
-1,1,0,-1,0
1,0,1,0,0
1,-1,1,0,0
-1,-1,0,0,-1
-1,1,0,1,0
0,1,0,0,1
1,0,-1,0,-1
0,-1,0,1,0
0,0,-1,1,-1
1,0,-1,0,0
The pieces can be interlocked in two layers of 5 pieces each with the top layer at 90 degrees to the bottom layer as shown in the above link.
I have already created a solution to this problem myself using Java but I feel that it was a clumsy solution and I am interested to see some more sophisticated solutions. Feel free to either suggest a general approach or to provide a working program in the language of your choice.
My approach was to use the numeric notation above to create an array of "Logs". I then used a combination/permutation generator to try all possible arrangements of the Logs until a solution was found where all the intersections equated to zero (ie. Peg to Hole, Hole to Peg or Blank to Blank). I used some speed-ups to detect the first failed intersection for a given permutation and move on to the next permutation.
I hope you find this as interesting as I have.
Thanks,
Craig.
