Bounded-Error Log

So winter vacation started and parents had planned a trip to southern Taiwan, to get closer to nature and walk around and stuff.

Also, the MIT Mystery Hunt, the absolute granddaddy of all the other puzzlehunts in terms of age, structure, and size, happened this weekend. Originally, I didn’t have a team and just planned to look at the puzzles after they got archived and try solving some puzzles read the solutions while constantly thinking, “How could anybody ever solve that?” Because of that, I wasn’t planning to even bring my laptop at first; then I could force myself to study some long-overdue ring theory during the nights. I was taken aback by a private message on Saturday morning from somebody with many different names inviting me to remote-solve for Random Thymes.

Me: !!!!!!!!!!

Sometimes, a sentiment randomly appears in my brain. I wonder about it. There’s a draft I’ve worked on because I’m trying to get something out of my bubble. My emotions are confusing and they need to be released.

And after a few sentences, they’ve been released, but the post’s not out there because I want to polish it. First it’s just a look-over for typoes or grammar, then maybe I want to get the flow of the sentences right or cut down the embarrassing bits.

Then, on the third read-over, I don’t know why I’m writing it anymore.

This is another MellowMelon’s Double Back. Briefly, draw a closed loop through all square centers visiting each bold-outlined area twice. Shaded cells do not influence solving, only aesthetics.

It’s mostly easy, I think. It’s okay if you don’t know what the theme means. (Yes, chao, I want more contrib points.) Also, WordPress seems to have stopped automatically linking images to their files. Hmm.

It’s been a while, hasn’t it? This is something I constructed semi-experimentally to stop failing at an entire genre of puzzles, and then procrastinated posting just about forever. I only test-solved this on paper; I hope I didn’t do anything silly while digitizing.

Rules paraphrased from USPC because I can’t find any good links: Write each of the given words into its own snail; letters must be entered from the outside of the snail spirally inward. Not all squares will be used; squares with “-” must stay blank. Each letter can appear at most once in each row and column.

Okay I don’t actually know how this pointless rambling got so long. I know the longer it is the more people will just tend to skim, because I do that all the time. So I went back and refactored—er, rewrote all the somewhat tangential bits (wow these puns are too easy) into footnotes. Manually. Obviously if I have to do this again I’ll write a script for it. But the post is still really long, and I bet nobody will read the whole thing. Oh well.

Life updates: I got out of the hospital Friday two-and-a-half weeks ago, went to the preliminaries of NPSC (a national team programming contest) with classmates, threw up a lot, went back into the hospital, and came out again. I wrote a lot of stuff about the experience and how much it sucked (hint: a lot) when I started this draft around that time, but now putting so much detail in this post feels weird. I’m mostly good now.

Three years ago NPSC was the only programming contest I really knew of; now I’ve participated in quite a few more, both online and locally, but it’s still the only contest I’ve entered that gives you real-time verdicts. I believe it inherits this from being modeled after ACM-ICPC, but that’s for college people and I’m less clear on how it works. All the other contests, namely TopCoder, CodeForces, USACO, and the other local individual competition (there doesn’t appear to be an English name so for the purpose of this post I’ll just call it “Nameless Local”; there’s a nation-wide competition in one-and-a-half weeks!), have system tests after the contest that don’t allow you to resubmit afterwards.¹ They all give pretests that you get to know about right away, just to catch super-silly non-algorithmic mistakes like failing to remove the debug statements or reading input from the wrong place, but these contain weak test cases and don’t guarantee that the solution will pass the system tests and get full score.

Noticed this at meander lawn who has a really broad puzzle blogroll… I don’t really know what I’m doing and may have misinterpreted something, but here goes. (Ahahaha puzzle 33 on 11/22… I wish it was intentional :P)

Draw a path through square centers which enters and exits through the given places. Outside the “ice barns” (the gray things), the path may turn freely but may not self-intersect; inside “ice barns” the path may self-intersect but may not turn. Each ice barn (not necessarily every cell but every region, I think) must be passed over. The path must pass through each given arrow in the given direction.

Yes, a “big” crazy mutant puzzle for a “milestone” (as seen on xkcd), both for this blog and for my life. Things are rough now, but I prepared this ridiculously ahead of time. It’s still not really big, but I’m not so experienced and I don’t have the inspiration for something like an entire mini-puzzlehunt. Also, I think I should attempt more word-bank-based puzzles some day so I won’t fail as completely at them.

But anyway: This is a Slitherlink combining MellowMelon’s Crosslink and Liar variations. Draw a loop through vertices that can intersect itself but must go straight both times if it does; each number normally indicates how many of the four edges around it are draw, but exactly one clue in each row and column is false. Have fun.

This is a Fillomino puzzle where every polyomino is required to be an L-shape, as in Sashigane. Write a number in every empty cell so that every group of cells with the same number that is connected through its edges is an L-shape (with arms of positive length and 1-cell thickness) with that number of cells.

My second, and now symmetric, attempt at this crazy self-invented mutant; puzzle 22 was the first. A word of warning: I can’t solve this without bifurcating near the end, so logic purists may be disappointed, but I like the clue arrangement too much. In fact I suspect this puzzle could have many more clues removed without affecting uniqueness, so tight are the rule constraints in this type.

Haha, way-overdue Fillomino-Fillia practice puzzle. This is a Fillomino puzzle; in addition to normal rules, treat numbers inside the grid as building heights. Numbers outside the grid indicate how many buildings can be seen from that direction, where a building blocks all buildings of lower or equal height behind it.

Edit: I should warn that the arithmetic here is pretty annoying.