Φθινοπωρινός διαγωνισμός προβλημάτων λογικής

 ΝΕΟ: Λυπούμαι να ανακοινώσω την επ'αόριστον αναβολή του προγραμματισθέντος διαγωνισμού, ελέω λειψού ενδιαφέροντος. Ευχαριστώ τους πρόθυμους συμμετέχοντες

Την Κυριακή 6η Οκτώβρη, μεταξύ 17:00 και 20:00, θα διεξαχθεί χρονομετρημένος διαγωνισμός προβλημάτων λογικής στο Καφέ Άλφα (Αλεξάνδρου Σβώλου και Εθνικής Αμύνης, Θεσσαλονίκη).
Πριν από το διαγωνισμό, στις 16:20, η διοργάνωση θα είναι διαθέσιμη για να συζητήσει τα προβλήματα και να απαντήσει σε τυχόν απορίες. Δεν απαιτείται πρότερη εμπειρία με τα προβλήματα λογικής

Ο διαγωνισμός θα περιλαμβάνει προβλήματα:

• Κάθε είδους: παραδοσιακά, μοντέρνα κλασικά, παραλλαγές και πρωτότυπα.
• Κάθε δυσκολίας: από εισαγωγικά ως επιπέδου παγκοσμίου πρωταθλήματος.
• Κάθε δεξιότητας: λεκτικά, αριθμητικά, τεμαχισμού, σχέδια, παρατήρησης κοκ

Οι διαγωνιζόμενοι χρειάζεται να φέρουν μαζί τους τα εργαλεία γραφής της αρεσκείας τους. Συνίσταται μολύβι και γόμα. Επιτρέπεται να φέρουν επιπλέον άγραφο χαρτί για λόγους σημειώσεων, το οποίο ωστόσο δεν βαθμολογείται. Επιτρέπονται επίσης γεωμετρικά όργανα. Απαγορεύεται η χρήση οποιασδήποτε υπολογιστικής ή ηλεκτρονικής συσκευής, η συνεργασία με άλλους λύτες, και η χρήση σημειώσεων ή βιβλίων αναφοράς.

Το αποτέλεσμα του διαγωνισμού θα είναι μία βαθμολογημένη κατάταξη. Δεν υπάρχουν έπαθλα, παρά μόνο τιμή για τους νικητές. Δεν υπάρχει τίμημα συμμετοχής, αλλά κάλυψη του κόστους διοργάνωσης θα εκτιμηθεί ιδιαίτερα. Οι διαγωνιζόμενοι της Θεσ/νίκης θα πρέπει να εκδηλώσουν ενδιαφέρον απαντώντας σε αυτό το μήνυμα ή με σχόλιο στην αντίστοιχη δημοσίευση στην ομάδα ηλεκτρονικού ταχυδρομείου μέχρι τις 10:00 της προηγούμενης ημέρας. Δεχόμαστε συμμετέχοντες που απλά εμφανίζονται στον ορισθέντα τόπο, αλλά δεν μπορούμε να εγγυηθούμε την ύπαρξη αντιτύπων για αυτούς. Οι συμμετέχοντες ενθαρρύνονται να κοινοποιήσουν τη διεξαγωγή του διαγωνισμού ευρέως.

Αν ενδιαφέρεστε να οργανώσετε το διαγωνισμό σε άλλη πόλη της Ελλάδας ή της Κύπρου, παρακαλείστε να δημοσιεύσετε εδώ. Τα υλικά του διαγωνισμού (φυλλάδιο οδηγιών, γύροι προβλημάτων, φυλλάδιο λύσεων και βαθμολόγησης) θα διατεθούν κατόπιν συνεννόησης.

Much too expensive

...for its intended use.

Another one in the unfair series I fear. This is a Price Tag puzzle. An addition of numbers formed by 7 segment LCD displays. No trickery like unlit displays, 0 prefixes, 1s made of left segments is allowed. Number forms are given. The clues indicate how many of that specific LCD segment are lit in the relevant row or column.

 

Quickly brushed off

Another Stardust puzzle.

Stardust 4

2⨉25

A 17⨉17 Yajilin of above average difficulty.

Yajilin 2

Minesweep under the rug

In these grids, some empty cells contain a single mine. A numerical clue indicates the number of mines in the eight adjacent cells. Stack all the grids on top of each other, and every cell stack will contain exactly one mine.

This is take two on writing a puzzle of this type, with a marked improvement in quality. Which is, in absolute terms, improvement from "abyssal" to "bad".

Brackish

A LITS of large size and average difficulty.

LITS 1 "Brackish"

Whirlpool

Overly symmetric puzzles tend to be boring. Creek puzzles tend towards the easy. Consequently, this puzzle should suck.

Creek 1 "Whirlpool"

Troll not

Regular readers of this blog, should such persons exist, may be excused for thinking the blog has turned into a convoluted trolling exercise, given the last couple of puzzles, which were unfairly, miserably hard. Hopefully, the masyu below starts to make up for those. It is of medium difficulty.

Masyu 9 "Make up"

Descriptive Pairs Tile Sudoku

For once, the title is, well, descriptive. Every cell in the grid below contains a number between 1 to 9, inclusive. All numbers in the same row, or column, or bold outlined box are different. There are 16 rows, 16 columns and 9 boxes. Clues outside the grid take the form of a pair of numbers. For numbers i,j this means at least one of:

• the ith cell contains value j or
• the jth cell contains value i.

I discovered Tile Sudoku, and this particular layout, on Grandmaster Puzzles. I first spotted the descriptive pairs variation on Prasanna Seshadri's blog.

Desciptive Pairs Tile Sudoku

Taking the piss

...out of people who woke up one fine morning to find out their company has been dissolved with absolutely no warning is now, apparently, a hobby of mine.

ert.gr screenshot

Turkey troubles

Yesterday, Serkan Yurekli posted a concise description of demonstrations and the harsh crackdown unfolding in Turkey. This is a courageous act, given the continuing arrests of protest information disseminators, and the horrors which threaten detained dissenters. Consider this post an expression of solidarity, and a call for police brutality to cease.

You can get a detailed picture of events and their direct drivers all over the web. I suggest Gawker (of all places) for a conversational overview, and this well-linked Ryan McCarthy piece as an introduction to current discussion.  Acemoglu has a few big-picture pieces on Turkey written prior to the events which seem to be on point. Finally, this video covers the government perspective of events.

Hateful Heyawake

This Heyawake hates you pretty thoroughly. You have been warned.

Heyawake 2 'Hateful'

Unlucky Nuribou

Nuribous aren't all that common. Rarity of a puzzle type trips up difficulty rating. What the constructor considers a trite pattern is more often a journey of discovery for the solver. My first instinct was to rate this as barely a medium. On reflection, hard will best set the expectations of a novice solver. No, not rules post-level hard, but still...

Nuribou 6 "Unlucky"

Easy pipelink

Rules. NB no cell is partially clued.

Pipelink 1

Stardust [Toroidal]

In addition to the usual rules, the grid is toroidal. That is to say, the top and bottom edges of the grid are connected the way they would if you bent the grid into a cylinder. So are the left and right edges. Or, for the fans of video games, think Pacman.

Stardust 3 [Toroidal]

Stardust

...of a reasonable size this time. (rules)

Stardust 2

Halo

Partition the grid into the given pieces. Rotations and reflections are allowed.

Monday Shopping

... with an easy Bag puzzle.

Bag 2

2V

I tend to go nuts when writing Hitori. This one is probably more accessible than the usual fare, though that isn't saying much.

Hitori 5

A small cryptographic fence

Draw a single closed line (the loop) on the yellow paths. The loop does not cross, overlap, or touch itself (no giggling back there) at a point. Letter clues exist inside the cells. Cells with the same letter have the same number of sides used by the loop. Cells with different letters have a different number of sides used by the loop. Yes, that number may be zero as well. Have, um, fun?

Easy Suraromu

And as usual, very susceptible to uniqueness. I almost chickened out of putting this one out. The design is so simple that it isn't entirely unlikely somebody else already wrote the exact same puzzle. Rules.

Suraromu 2

NoriOrNot

This started out as an experiment in developing large scale constraints for that apparently hopelessly local problem, Norinori (rules). I'm not quite there yet, but I'm working on it. I'd like to hear how much exploration each solver found necessary.

Norinori 2

A bigger Magic Order

One of these days I'll write one that is both pretty and pleasant I promise. (Rules)

Magic Order 2

Another Connecting Wall

of mine is right here. I wish I could go back and edit one thing, but oh well. What one needs to do is partition the cards into four stacks of four, then figure what the items of each stack have in common.

Got a minute?

This masyu is not likely to take more time than that.

Like a Venice

Tricky Bridges problem. Or not, if I missed any shortcuts. I'd like to hear how people attack this one; also, whether the broken design convention annoyed them. (Rules)

Hashiwokakero 2

Threatening sky

Sky's promising rain here. So here are some puddles. Specifically, Pentomino Puddles (rules)

To dust

This is a Stardust puzzle (rules) with, hopefully, no extraneous stars. And second rate graphics. Maybe next time it's going to be based on some actual constellations.

Stardust puzzle 1

Magic Order

Write a digit from 1 to 5 in every cell. Digits in the same row and column are all different. Reading these digits from left to right, from right to left, from top to bottom, and from bottom to top forms twenty different 5-digit numbers. Clues before the number give their position in an ascending order.

This is rather nasty for such a small grid.

EDIT: fixed

Hip hip...

Sudoku

Twenty one

When going to 11 isn't enough...

Every row, column and outlined region contains all numbers from 1 to 8, one per cell. All adjacent cells which differ by 5 are marked by a dot on their common border. Symbols outside the grid indicate a property shared by the first two cells in that direction. Same symbols mean same property, different symbols mean different property. Possible properties are:

• Big: number is 5,6,7 or 8.
• Small: number is 1,2,3 or 4
• Odd: number is 1,3,5 or 7
• Even: number is 2,4,6 or 8

Enjoy.

Pearlorrhea

This started life as a small Masyu meant to showcase an interesting pattern. I'm not quite sure how it ended neither small, nor a showcase for said pattern. On the tricky side of average far as difficulty is concerned I guess.

Way of the milk

Very easy; also, celebratory.

Happy New Year!

So 1/12 of the year has gone past before I got around to this blog. In my defence, when I set off on that Mystery Hunt runaround, I thought I'd be home by January. [rimshot] And, talking of gargantuan puzzles, here's a Country Road I got bored of putting together about three quarters of the way through. See if you can spot the late additions.