Monthly Archives: February 2009

Solver for KenKen puzzles (Representation)

Posted on February 27, 2009 by MXH

One of the biggest differences between KenKen puzzles and Sudoku puzzles is that the former are harder to represent compactly. Sudoku puzzles can be represented as a simple string of numbers, but the 2-dimensional cages of KenKen puzzles seem to … Continue reading →

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Solver for KenKen puzzles (Constraints)

Posted on February 26, 2009 by MXH

Today I’m going to show the Constraint implementation for a KenKen solver I’m building. This code will cover all the rules of the KenKen game, and will shortly be used in a constraint propogation and search algorithm. It contains several … Continue reading →

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Solver for KenKen puzzles (Constraint design)

Posted on February 25, 2009 by MXH

Following up on yesterday’s post, I’d like to get started on the construction of a solver for KenKen puzzles, using the same basic constraint-propogation-and-search approach that Norvig used in his Sudoku solver. I’m going to begin with a discussion of … Continue reading →

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KenKen vs. Sudoku

Posted on February 24, 2009 by MXH

According to Slate, there’s a push afoot to popularize a Sudoku-like game named KenKen. Since it’s already been demonstrated that Sudoku falls easily to a little programming, I thought it would be interesting to (informally) compare and contrast the two … Continue reading →

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Details Matter

Posted on February 23, 2009 by MXH

I was looking at Norvig’s Sudoku solver the other day, and suddenly understood a design choice that had previously struck me as bizarre. I think it’s a neat example of how small, seemingly arbitrary things can make your programming either … Continue reading →

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Skiing

Posted on February 22, 2009 by MXH

I am not a good skier. I can look ok on the majority of intermediate slopes, and make my way down diamonds. I’ve never been on a double-diamond in my life. I have a lot to learn. However, I have … Continue reading →

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Antisocial Product Idea

Posted on February 21, 2009 by MXH

Why, oh why, doesn’t anyone make Bear Treats? (These don’t count.) The box copy practically writes itself: Three flavors: Salmon, deer, and refrigerator medley Delicious, tasty aroma (travels hundreds of yards) Loved by both cubs and adults Irresistible – Bears … Continue reading →

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Usage of Redundant 8086 Opcodes

Posted on February 20, 2009 by MXH

This is a follow-up to last week’s post, which discussed the fact that fully 30% of the 8086 processor’s 1-byte opcode space is given over to redundant opcodes (i.e. short forms of longer, more general opcodes). Today, I want to … Continue reading →

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Mac OSX Tip

Posted on February 19, 2009 by MXH

A useful little tidbit from a friend of a friend: Hiding a CLI-only user account in Mac OS X 10.5 Leopard

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Python Puzzle

Posted on February 18, 2009 by MXH

Pedram Amini has got a pretty neat post up on reverse engineering the protocol for a USB device. If you haven’t seen it yet (it was linked from Slashdot) it’s worth reading. However, he includes some Python code which features … Continue reading →

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