New Toy
I got a new toy last week. Today I discovered that the colours on it match the ubuntu palette.
I thought my computer was being sluggish, and I didn't know why. It turned out that it was just my left mouse button dying, and hence the computer seemed unresponsive.
Now I have the left/right buttons switched, and for some reason, it is putting my mind into "whacky input mode", and I keep on thinking the keyboard is dvorak.
For the cube, it is pretty much the same as any other > 3x3 rubik's cube, except bigger and more awesome. With the larger cubes, if you solve them the way I do (and I think most other people do) you get parity issues, where you get really close to the end, and then realise that some pieces are out of place and if you just use the set of moves you have been using, then you won't be able to fix them. Up until a few days ago, my solution had been to scramble the cube and try again.
Wikipedia originally made me think that it wouldn't have parity issues:
Because the centers, middle edges and corners can be treated as equivalent to a 3x3x3 cube, the parity errors sometimes seen on the 4x4x4 and 6x6x6 cannot occur on the 7x7x7 unless the cube has been tampered with.
But it was just referring to the parity issue you get with the even sized cubes that you don't discover until the very end. With the 5x5 and 7x7, you realise there is a parity problem a bit sooner, but it is still there. My first solve I got lucky and had no parity problems, which confirmed my misreading of wikipedia. The second time around, I had a double parity problem, which made me think that I should get a method for deterministically fixing the parity problems (which I have now).
I have a square-1 puzzle which I've solved once. Unfortunately my algorithm wasn't general enough to work all the time, and I don't have a good sense for probabilities on those puzzles, so I don't know what the chances of it working are (my guess would be 1/8 or 1/16). I think my big problem with the square-1 is that it is difficult to remember the state of the puzzle before you do a move sequence, so you can work out what has changed. Even notating a move sequence is difficult. (though I don't understand the notation people use for rubik's cubes either).
RSS