Sunday, February 14, 2010

Bring Your Scarlet Lips To Me, Sit Closer To This Fine Lad

Thinking caps on, class, it's puzzle-solving time. And with prizes!

A while back, I had an idea for a gift for a friend. I bought a bunch of perler beads and made a series of video game characters (using actual sprites for reference, thank you very much). They were intended to be Christmas ornaments (just stick a little hook through the top of them), but when I found out that he usually doesn't get a tree for himself, I needed a backup plan. You know, something else a bit more utilizable. In the end, I thought of Fridge Tetris, a bunch of Tetris-shaped magnets.

I asked the recipient to make a YouTube video of their reaction when they opened the package, and he definitely seemed to enjoy his new toys. "This is quite possibly the coolest thing in the world, and I've been... Okay, I haven't traveled that much, but... This is still really, really cool!" Mission accomplished, I'd say.

Since then, I've been returning to the idea of Fridge Tetris as gifts for people. It only takes a couple hours to make (and that's while watching Schlag den Raab), and I already have a large supply of beads (maybe too large? I need to kill those off...), so I figure, why not? Other recipients have reacted with similar amounts of glee, so I know it's a fun idea worth repeating.

The problem, however, lies in the setup process. I always make sets of 28 blocks (four each of the seven shapes), and I try to knock them all off in one ironing session. I have these large square pegboards that I make all of the pieces on, but no matter how hard I try, I can't seem to squeeze them onto one board. I end up with about 25 pieces on one board, three on another, and my first time ironing them didn't end well, as the iron knocked some of the pieces out of place when sliding over to the second board. I've avoided this in the past by making multiple sets and spreading the pieces more evenly across three boards, but I'd rather find a way to make a single set on a single board.

Here's the puzzle.

I'm looking for a way to fit all 28 pieces (again, four each of seven shapes) onto one pegboard. The dimensions of the board are 29 pegs by 29 pegs. Each piece consists of four touching 2x2 squares, as shown in the picture. (Thus, the famous "LINE PIECE!" is a 2x8 rectangle, while the "SQUARE PIECE!" is a 4x4 square.)

Some other rules to keep in mind:
--The pieces may not touch. This includes all sides and corners. While I know that it's easily possible to snap apart things joined at the corners, I would prefer that the pieces keep their rounded edges, rather than a random flat edge where a border once occurred. There must be a one-peg border along all sides of the piece, with the exception of the outermost edge of the board.
--Pieces cannot be flipped. While you could argue that a S is the mirror image of a Z (sorry, "SQUIGGLY" and "REVERSE SQUIGGLY"), I also apply more pressure with the iron on the first fusing before flipping the pieces over to fuse the backs, and the more-fused sides usually become the side I put the magnets on. To prevent inconsistencies in appearance, I would prefer that the pieces are in their proper orientations on the board. (The same applies for the J and L pieces.)

Ultimately, what I am trying to find is whether or not it's possible to make the 28 pieces on one board given the above rules. If it's not possible, then it's not possible, and I guess there's nothing I can do about that, but if it is possible, the first person who presents a valid solution will receive a free set of Fridge Tetris magnets. Fine print: Colors may vary. Product will be made and shipped at my convenience, I'm on a schedule too, you know.

I know I've got to be forgetting some other rule or restriction, but I can't remember it for the life of me, so go nuts. If I remember it, I'll add it here. Submit your questions and solutions in the comments box. Thanks, and good luck!

Update: Congrats to Derek for coming up with this solution, tweeted to me in an amusingly small 29x29 picture. For some reason, it seemed natural to repost it as a snapshot of an Excel spreadsheet so you could see the gridlines. So, Derek gets some Fridge Tetris lovin', but it's not too late to get your own batch! See the comments for more details...


zxo said...

Done. Check your tweets.

Stephen Lewis said...

I am impressed to the point of confusion. Wow. Well, it looks like we might already have a winner! I'll double-check that tonight (and try to post a picture of the solution in action), and I'll get it into the mail to you sometime this weekend. (Do I still have your address? Email or FB it to me just in case.)

Now then, for the rest of you! I kinda wanted to do this as a side-contest, but since the first one ended so quickly, here's contest two: I obviously made this post on Valentines Day. But lovey-dovey message aside, what's the significance of the title of this post? First responder with the answer wins a set of Fridge Tetris. (Derek, you've already won, so you're obviously DQ'd here.) It's as simple as that...

No but seriously, it's probably literally as simple as being the first to do a Google search and post the answer. Which means you pretty much have no excuse! WHO WILL WIN?

ksekelsky said...

It's from the translated lyrics to the Russian folk song that the Tetris song is based on.

Stephen Lewis said...

Aaand win. Contest(s) now closed, and I'll be working to get both of your sets in the mail hopefully sometime this week.