we have a project in our class to design a sliding numbers game similar to this one:

http://www.eatmygames.com/gameinfo.asp?id=24puzzle

the only difference is that the number of blank spaces is user input (max=n/2 where n: no of elements in a row/column).

we have to design an algorithm to make the computer solve the puzzle on its own.

can we get some ideas for the AI part? we're totally stumped!

PS: I know this counts as homework, but I just need a hint for the algorithm. we can take it from there onwards.