## Friday, June 27, 2008

### Rubik's Cube non-walkthrough

Ok, so I can solve the Rubik's Cube. You're probably not surprised. Well, if I may boast a bit here... I've been able to solve it for at least seven years. I figured it out completely on my own, without any walkthroughs. No, I didn't even ever see the hint booklet that comes with the Rubik's Cube. Ours was really old, and the hint booklet was long gone. As a result, I solve the cube in a completely different order than most people do (I think the way I do it makes much more sense). I also own a 4x4x4 Rubik's Cube (16 squares to a face) and can solve that.

The internet will probably not be impressed--not until I can videotape myself solving it in 30 seconds while simultaneously doing interpretive dance. But in real life, people tend to be impressed. The thing is, people don't realize how easy the Rubik's Cube is. There are a few very simple principles to solve any permutation puzzle. By permutation puzzles, I mean the kind of puzzle where you have to arrange the numbers in the right order, put the cubies in the correct place, or otherwise sort a number of items into the "correct" order. I'm not going to go into the details of how to solve the Rubik's Cube. I'll do better: I'll reveal the secret to solving pretty much any permutation puzzle without a walkthrough.

Step 1: Sort as many items as common sense will take you. On the Cube, most people solve one face; I solve for some other weird combination. This is where most people tend to fail--luckily, this step is skippable.

Step 2: Develop several algorithms that will change the position of only a few items. That way, you can solve the remaining part of the puzzle without messing up your previous work. Developing an algorithm is pretty much a trial and error process. Just try a bunch of moves, write down the steps, and note the changes. Once you find an algorithm, it behaves like a blackbox--you can just memorize the process without knowing exactly what's going on during the process. (However, if you're good, you can open the blackbox, and manipulate the algorithm without trial and error.)

Step 3: Combine these algorithms to solve the rest of the puzzle. The difficulty of this step depends on how good your algorithms are. For example, if you find a way to simply switch two cubies, you can easily repeat this over and over, putting each cubie into its place one by one. However, it is impossible to find any such algorithm on a Rubik's Cube. You must switch at least three cubies at a time. But if you've got enough thinking power, such an algorithm is enough to solve the puzzle. (Incidentally, you can switch two cubies for the 4x4x4, though there are other limits to what you can do.)

And that's it! Easy, right? Well, if you were looking for a solution to the Rubik's Cube, I probably didn't help you in the slightest bit. But now you know what you're looking for.