15puzzle Optimal solver

"15puzzle Optimal solver" for windows.

Version 1.2 (MAY/2002)

1. Introduction: 15puzzle is a sliding block puzzle which Sam Loyd devised in 1878.
This software finds a optimal solution of the 15puzzle.

2. Operating system: Windows.

3. Download: 15puzzle.zip (267KB)

      If the layout fails, please download this.
          15puzzle.exe (580KB) (JUN/2007)

4. Installation: This software runs only by the one file "15puzzle.exe".

5. Basic usage: A click of [SHUFFLE] button shuffles pieces using a random number.
A click of [SOLVE] button finds a solution of the optimal path.
A click of [PLAY/Trace] button displays the found solution.
Please try suitably except it.

6. Algorithm: This program uses IDA* as the basic search algorithm.
And this uses WD(Walking Distance) to improve the efficiency of the search.
WD is a sophisticated lower bound for how many moves are needed to solve an arbitrary board configuration.
WD gives severe distance than MD(Manhattan Distance).
As for the details of WD, please read here.(Japanese) Or Picture

7. Author: Ken'ichiro Takahashi (takaken), JAPAN.