IPC 2012 Puzzles

Last weekend, the 2012 Indian Puzzle Championship was held at LMI. Like last year, I provided some of the puzzles for it, alongside Deb Mohanty, Serkan Yurekli, and Thomas Snyder. Six out of the 30 puzzles were mine; I’ve reproduced them in this post for anyone who hasn’t seen that championship. Enjoy.

Puzzle 392 (Masyu) [Yajilin]

This is a Masyu puzzle, with a twist. Two squares that are unused by the loop may not be adjacent (this is a rule borrowed from Yajilin).

Puzzle 392

Puzzle 373 (Masyu) [Optional Blacks]

This is a Masyu puzzle, with a twist. The loop is not required to pass through black circles. But if a black circle is passed through, it still functions like it would in ordinary Masyu.

Puzzle 373

(Click for larger size)

The gimmick in this puzzle means that trial and error strategies are likely to get you the solution in short order. So I did my best to make the logical path as clean as possible, and I mostly succeeded. For maximum enjoyment and challenge, avoid any if-then sequences of significant depth.

Puzzle 364 (Masyu) [Optional Blacks]

This is a Masyu puzzle, with a twist. The loop is not required to pass through black circles. But if a black circle is passed through, it still functions like it would in ordinary Masyu.

Puzzle 364

(Click for larger size)

Unrelated to this puzzle: it occurred to me recently that it’s been over a year since the Numberlink solving primer went up, and I haven’t really done any sort of solving guides since then. It’s not for lack of time or desire, but mostly because I have no idea what to write for and what people might want to see. The Numberlink guide itself had been directly inspired from some comments on a recent (at the time) puzzle of mine.

If there’s a type or anything solving-related that you’d like to see a guide for, I’d be happy to hear the request. While there are some things, particularly Latin Square based puzzles, that I have no authority to write on, I think there’s a fair amount I could do.

Puzzle 347 (Masyu)

This is a Masyu puzzle.

Puzzle 347

(Click for larger size)

Puzzle 300 (Loop of Death) [Unique]

This is a Loop of Death puzzle, a unique type. Almost all of your favorite (and unfavorite) loop puzzles have been combined into a single type. Detailed rules, along with an example, follow below the image and comments.

Puzzle 300

(Click for larger size)
3/20/2011 5:22 AM ET – Fixed a goof in the far bottom right corner that resulted in no solutions by a minor change to the regions. You probably found this contradiction if you made any progress at all in that area. My apologies.

As far as my marathons/unique puzzles go, my guess is this is probably tied for the easiest – size has something to do with that – but I could be completely off in either direction. Of course, this still means it is going to be really hard.

Grid size is 29 by 29 squares. This means 30 by 30 for the vertex clues, although I never used any of the edges. From that, I’m sure some of you are going to figure out what puzzle I paid homage to in constructing this one, but I’ll leave to you all to guess.

Melon’s Puzzle Zoo has ended

Around the time of this posting, LMI is no longer accepting score submissions for the contest. Below is a link to the puzzle booklet, the same as the one on LMI without the password. There is also a PDF that has all of the puzzles on the test together with their solutions (don’t open if you don’t want to see them yet!), as well as some brief comments from myself about the puzzles. Mostly I pointed out the tricky innovative logic the puzzle had, if any — and for the adults there almost always was some.

Puzzle PDF
Solution PDF

Puzzle 290 (Castle Wall / Masyu)

This is a Castle Wall / Masyu hybrid puzzle.

Puzzle 290

Part 9 of 12 in the Melon’s Puzzle Zoo preview series.

Answer Entry: Some squares are marked with letters. For each letter in alphabetical order, determine how many of the nine squares bordering the lettered square, including the square itself, are used in the loop. Enter these digits in alphabetical order by letter.

Highlight to see answer: 648583

Puzzle 256 (Masyu)

This is a Masyu puzzle.

Puzzle 256

Puzzle 207 (Masyu)

This is a Sunday Masyu puzzle.

Puzzle 207

I’ll admit this could have come out a bit better – it’s no juno puzzle to be sure – but I still like it how it is. There are a couple of very difficult steps, so be prepared to stare a bit. Then again, I suppose most of you already know what my Sunday puzzles are like by now…