8 Puzzle Problem

The 8-puzzle is a square board with 9 positions, filled by 8 numbered tiles and one gap. At any point, a tile adjacent to the gap can be moved into the gap, creating a new gap position. In other words the gap can be swapped with an adjacent (horizontally and vertically) tile. The objective in the game is to begin with an arbitrary configuration of tiles, and move them so as to get the numbered tiles arranged in ascending order either running around the perimeter of the board or ordered from left to right, with 1 in the top left-hand position. An example scenario is shown below.

8 Puzzle Initial State 8 Puzzle Goal State
Initial State Goal State

Here the goal state can be reached from the initial state at 5 simple steps given below.

  1. Blank Up
  2. Blank Up
  3. Blank Left
  4. Blank Down
  5. Blank Right

As mentioned earlier the goal state has two possible arrangements. These arrangements can be:

8 Puzzle Goal State A 8 Puzzle Goal State B
Goal State A Goal State B

If you are willing to solve 8 puzzle problem, determining the goal to be reached from an arbitrary initial state can be tricky. A suggestion on the choosing the goal state is given in the 8 puzzle algorithm section of the site.

Also you can find the download link to the software that solves any given 8 puzzle problem with minimum number of moves in the 8 puzzle download section of the site.