Aart's Blog

My daughter just started to learn addition and subtraction in school. Like a true nerd, I wrote a Java applet to generate math worksheets, so that I no longer have to write out exercises by hand. To try it out, go to math worksheet generator . Click on the top-right +/- buttons to increase and decrease the level of difficulty, click on the ADD/SUBTRACT button to toggle between additions and subtractions, or click anywhere to generate new exercises. Feel free to print the math worksheets for your own use (unfortunately, this may not work for some browsers).

I made minor improvements to the reversi move generator and evaluation function in version 1.5.5, hopefully resulting in stronger play. Unfortunately, in my excitement I forgot to add a new internal state to the save/restore functionality, which could introduce wrong play if a game was exited and later resumed. This has been fixed in version 1.6 of Reversi for Android. Many thanks to Patrick Barnes for reporting the bug (with a screen shot as illustration!).

I just posted version 1.5 of Chess, Checkers, and Reversi for Android at the Android Market , all with the much requested "save on exit" feature. If a user exits a game in progress, the game is automatically saved and later restored when the application is restarted. Even if the interrupt happened while the engine was thinking about its move, the game will restart in that state (albeit taking the full allocated time again). Apologies to all users who have been requesting this feature for a while, I just needed to find some time for it.

With tears in my eyes I read the news and watched the pictures of the senseless attack on the Dutch royal family by a man who crashed his car through the crowd during the annual Queen's Day celebration. I pray for the victims and those who mourn.

Version 1.4 of Chess for Android is now available at the Android Market with the following new features: Two improvements in the engine: removed unnecessary restriction on search depth and fixed bug that could cause an out-of-bounds exception. The engine now detects draw by a simplified form of three fold repetition. The detection is not complete, since only limited game history is kept; but at least this new feature avoids some very annoying repetitions. Draw by the fifty move was already implemented. A new level "Auto-play" has been added (press the Menu button). If this level is selected, then the next time the engine takes control (make either a move or touch "Reverse sides"), the game is played automatically.