Greg Hewgill (ghewgill) wrote,
Greg Hewgill
ghewgill

mahjongg widget

I'm back to writing more widgets using the Yahoo! Widgets framework. This one is Mahjongg, the terribly addictive tile removal solitaire game. It includes an option to generate either a random initial game, or one that is guaranteed to have a solution. It also (optionally) times your game and keeps track of your fastest time.

Interestingly, the most difficult part of writing this was writing the algorithm that generates a solvable game. The general idea is to work backwards: Start with a blank board and place pairs of matching tiles on the board (in legal positions) until you reach the starting point. Then the solution is just doing the same thing the other way - ie. forwards, like you would play it. The problem is there are ways that the game generator can sort of paint itself into a corner. For example, if you have two tiles left to place on the board (which would be the first move of a solution), you can't place them side by side on one end of a row, because the player won't be able to remove them that way. If the game generator encounters such a situation, it just gives up and tries again from scratch. On average, the generator has to start over once or twice per valid generated game.

Tags: widgets
Subscribe

  • othello widget

    I've released another Yahoo widget - Othello. This was one of the first widgets I actually put together a couple of years ago (based on my Othello…

  • widget goodness

    I've been busy putting together yet another widget: Card Games. This one implements a few solitaire card games - currently Klondike (classic…

  • foiled again

    So I finished my earthquake widget about a week or so ago. I was waiting to send it to the Yahoo Widget Gallery so that the screen snapshot they…

  • Post a new comment

    Error

    Anonymous comments are disabled in this journal

    default userpic

    Your reply will be screened

    Your IP address will be recorded 

  • 5 comments