# IPC Preview – Practice, Solving Tips, Links

Update: Fixed the typo in Pentomino Kakuro. New PDF uploaded. No other change.

Update: There is an erratum published on the IPC site that says the 2×2 restriction applies to Happy Dots too. Since the practice puzzle in the PDF still gives a nice practice for placing the dots and forming regions, and only uses 2×2 regions minimally, it stays the same in the PDF. We’re sorry for the inconvenience.

If you’re having trouble with some puzzles, seeing/adding to the discussion in the comments might help. (This also serves as a spoiler alert for those who want to work on the puzzles without help)

Right, took a while, but we’re finally there. If you’re still not aware, the Indian Puzzle Championship will be held on 7th July. Here are our (me and Swaroop) best efforts, with the main goal being to try to help the newer participants.

This PDF features –

1. Practice puzzles for B1, B2, C, D, E2, F1, F2, G2, I1, I2, J1, J2, K1, K2, L1, L2, M2.

2. Beginner-level solving tips for all the puzzles in the set.

3. Solutions to all the puzzles in the set.

4.  Links to other practice material, pattern guides, and other technical tips.

Enjoy!

# Puzzle No. 382-396 : Czech Puzzle Championship Puzzles

I think this was a set I wrote when I wasn’t that well. That’s not meant as an excuse, but as a warning – I tend to make things harder when I’m ill. However, some of these are also rejects from newspaper bunches for being not-too-easy (Heyawake for example) which means there’s some easy in there too. Unlike my previous puzzle set posts, I decided to find out a bit more this time, which basically means that I can add the points that were assigned to each puzzle. The Skyscrapers Pentomino was not used, but since it was not used for being too hard, I’ve simply valued it at points higher than any of the others.

The Championship had 5 rounds and then a playoff at the end. The first round had the largest time slot and so two of the hardest puzzles of my set, the Yajisan Kazusan and the Shakashaka were moved into that round. Two others, Heyawake and Multiplicative Corral were moved to the Playoff/Final. There’s no point valuing for these, but I’d put their difficulty around the LITS or the Country Road, something of a medium difficulty.

There were 25 participants, and Jan Novotný emerged as the winner, mainly by having a good playoff, as Matej Uher was ahead after the first 5 rounds (377.8 – 299.2). In fact, Jan was 4th before the playoffs, behind Jana Vodičková (332.5) and Jakub Hrazdira (306). Congrats to him, and the other qualifiers. For my round (the 4th round, valued at 110 points), the top scorers were Matej Uher (85), Jakub Ondroušek (77) and Jakub Hrazdira (62). I’m posting only my own puzzles but as a test solver for the event in general, I did have access to the other puzzles too, and the quality is quite high throughout. If you’re interested in knowing more, or you are a Czech/Slovakian interested in becoming a member of the HALAS Association (where I think you will gain access to all these puzzles), I’d suggest you contact Jiří Hrdina, who co-ordinated/organized this Championship.

P382 : Bosnian Road (8 points).

P383 : Country Road (12 points).

P384 : Easy As Tapa (14 points) – Follow regular Tapa rules. Clues outside must be placed in the first unshaded cell in that row or column.

P385 : Fillomino (7 points).

P386 : Heyawake (Playoff puzzle).

P387 : LITS (12 points).

P388 : Masyu [Alternative] (4 points) – Follow regular Masyu rules. Additionally, the loop cannot pass two circles of the same colour continuously.

P389 : Multiplicative Corral (Playoff Puzzle) – Draw a single closed loop along the grid lines that contains all the numbered squares and does not touch itself, not even at a point. Each given number is the product of two numbers: the number of interior squares that are directly in line vertically with that number’s square (including the square itself) times the number of interior squares that are directly in line horizontally with that number’s square (again, including that square itself).

P390 : Nanro (14 points).

P391 : Norinori (5 points).

P392 : Product Heyawacky (25 points). Follow regular Heyawacky rules. Additionally, the number at the top left of a cage is the product of shaded cells in each different region, only pertaining to its area within the cage.

P393 : Shakashaka (40 points).

P394 : Skyscraper Pentomino (60 points?). (Edit – It should be noted that the puzzle in the link has “X” marks where pentominos can’t be placed, whereas the puzzle below has black cells denoting that)

P395 : Sum Skyscraper (9 points). Follow regular Skyscrapers rules. This skyscraper uses the digits 1~7. The numbers outside indicate the sum of the visible digits.

P396 : Yajisan Kazusan (40 points).

Now, the puzzles! Enjoy!

P382

P383

P384

P385

P386

P387

P388

P389

P390

P391

P392

P393

P394

P395

P396

# Puzzle No. 351 – 366 : Zagreb Open puzzles

I managed to somehow squeeze this set out in one day just before my exams started, right in the middle of the hectic submissions time in college. After that, Vladimir managed to squeeze in some time on that day itself to test these puzzles, so many thanks to him for that.

Rules all placed at the start of the post with the puzzles coming later (Trying a new format for posting, simply because its more convenient for me. The puzzle captions should aid you in knowing which rule is for what puzzle, but the ordering is the same as well, so it shouldn’t be much hassle either way.

Rules –

351 – Akari.

352 – Fillomino.

353 – Graffiti Snake.

354 – Heyawake.

355 – Japanese Sums – Place the digits 1-6 in some of the squares, so that no digit is repeated in any row or column. Sums on the outside indicate the sums of consecutive digits in that row or column, in order. Each sum is seperated by at least one empty square.

356 – LITS.

357 – Nanro – Write numbers in some cells of the diagram. All numbers in a region must be equal. The given number in a region denotes how many cells in this region contain a number (at least one). Same numbers must not be orthogonally adjacent across region boundaries. Numbered cells must not cover an area of size 2×2 or larger. All numbered cells must form a single orthogonally continuous area..

358 – Odd Even Skyscraper – In addition to Skyscraper rules linked to below, all outside clues that are shaded are odd. The rest are even. Range 1-6.

359 – Pentopia.

360 – Regional Yajilin.

361 – Shakashaka.

362 – Skyscrapers. Range 1-6.

363 – Tapa.

364 – Tents – Place a tent ortogonally next to each tree so that no two tents touch eachother, not even diagonally. Numbers on the outside indicate the amount of tents that are in that row or column.

365 – Walls Fillomino – Some region borders are given; i.e. the numbers on both sides must be different.

366 – Yajisan Kazusan.

Enjoy!

P351

P352

P353

P354

P355

P356

P357

P358

P359

P360

P361

P362

P363

P364

P365

P366

# Puzzle No. 316 – 336 : Polish Championship set

I’d mentioned a few posts earlier, that I’d contributed some puzzles to the Polish Championships this year. There was an offline qualifier, an online qualifier, the finals, and the playoffs. I think there was a good share of my puzzles in all 4 of these rounds. Its pretty confusing which was used where, since I’ve not organized it that well in my folders, so I’ll just post all the themed ones together (as mentioned in that post linked to above, the online qualifier had puzzles that I used simultaneously elsewhere and were more of a hurried solution).

The theme I was working on should be pretty obvious on seeing all the puzzles. It started with the easier Tapa, which I made completely by accident while writing a bunch of newspaper puzzles, and then I just tried a similar thing with the Corral and that happened quickly too. So, just decided to go along with it, discarded those two from the newspaper bunch and started off the Polish set with them. I couldn’t really try and retry the puzzles to get the exact appearances I wanted, and this is apparent from the 2 LITS and the Killer Sudoku among other ones. The LITS is of course something difficult that I set myself to do in a pretty short timespace, as both LITS were required hurriedly for the qualifiers, and to make it have duplicated regions throughout on the first try seems almost impossible, at least for me.

Anyway, here they are. As with the Zeka set, rules are either linked to by the puzzle names or just added here. These puzzles have varying difficulties, but I don’t think anything was exceptionally hard.

Enjoy!

P316 – ABC Box – Fill the grid with letters A, B and C. The clues outside give the sequence of letters in that row or column. If the clue is a number, that is the number of times a letter appears in that position of the sequence (Which letter is determined while solving). If the clue is a letter then that letter appears in that position of the sequence (The number of times it appears continuously is determined while solving). A “?” means that an unknown letter is appearing an unknown number of times in that position of the sequence.

P316

P317  : Akari.

P317

P318 : Corral.

P318

P319

P320, 321 : Fillomino.

P320

P321

P322 : Heyawacky.

P322

P323 : Killer Sudoku 8×8 – Follow regular sudoku rules. Additionally, the numbers at the top left of a cage gives the sum of numbers in that cage. Numbers cannot repeat in a cage.

P323

P324, 325 : LITS

P324

P325

P326 : Masyu

P326

P327 : Pentasight

P327

P328 : Pentopia

P328

P329, 330 : The Persistence of Memory

P329

P330

P331 : Regional Yajilin

P331

P332, 333 : Tapa

P332

P333

P334 : Tapa Skyscrapers

P334

P335 : Yajilin

P335

P336 : Yajisan Kazusan

P336

# Puzzle No. 297 – 312 : Zeka 2013 Puzzle Set

I realize I’m crossing 300 with this without the usual special puzzle, but with Puzzle Marathon coming up, I’m sure everyone will have their fill of special puzzles. I’ll make it up later sometime between 300 and 400. Anyway, this was a 1 hour set at the Croatian competition. I basically started off with trying 1 classic puzzle and one variant of it, but then some pairings are just similar genres. For the variants, I’ll just put the additional rules. The Classic puzzles have links to their rules, and some are fully described here. The difficulties are obviously varied but barring the Pentomino I can’t immediately think of anything particularly difficult. All puzzles tested by Bram De Laat.

Enjoy!

P297

P298 : Bosnian Road Odd Even – The clues only give the information that the number in that clue cell is either Odd (O) or Even(E). All the clue substitutions are non-zero.

P298

P299 : Masyu.

P299

P300 : Corral Masyu – The cells not visited by the loop must be able to reach the edge of the grid by being orthogonally connected to other such cells.

P300

P301 : Hashi (Probably the easiest puzzle of the set) – Draw single or double straight lines between the circled numbers. The number in a circle indicates how many lines must end there. The lines must run horizontally or vertically and must not cross or branch off. All circles must be connected to each other; i.e. it must be possible to travel from any circle to any other circle following the lines..

P301

P302 : Gokigen naname (Known as Slalom in some places like Croco Puzzle) – Draw exactly one diagonal line in each cell of the diagram. A number in some intersections of the grid lines denote how many diagonal lines end in this intersection. The diagonal lines must not form a closed loop.

P302

P303 : Norinori

P303

P304 : Trio Cut – Paint some cells to make some triminos so that each trimino will be cut twice by thick lines. Each region bordered by thick lines should have 3 painted cells.

P304

P305 : Easy As ABC (Range – A-C)

P305

P306 : Easy as ABC Untouch – Additionally, same letters cannot touch each other even diagonally. Range is A-D.

P306

P307 : Nurikabe

P307

P308 : Cipher Nurikabe – The numbers are replaced by letters. All instances of the same letter have same values and different letters have different values. Note that the rule says values, so one letter can stand for a multi-digit number too.

P308

P309 : Tapa

P309

P310 : Disjoint Groups Tapa – Additionally, clues in the same box cannot have the same position around them shaded. E.g. 2 clues in the same box cannot both have the cell directly above them shaded.

P310

P311 : Pentomino – Place the 12 Pentomino pieces into the grid. They can be rotated and reflected. They cannot be placed in black cells. Two pieces cannot touch each other even diagonally. The numbers outside give the number of cells occupied by pentomino pieces in that row or column. Pentominos given at the end of the post.

P311

P312 : Pentomino Areas – Instead of the numbers outside, the grid is divided into regions, each of which consists of exactly one entire pentomino.

P312

# Puzzle No. 264,265 : A Skyscraper Sudoku and a Skyscraper Pentomino

I have a new gmail id! I have updated my About the blog section with this and my facebook address. Not sure exactly why, but approachability is the vague reasoning I guess. I shall also soon add a few more links as my favorites. I’ve been meaning to do so for a loooong time, and should finally get around to that during the weekend.

I didn’t want to use the obvious Puzzle complement like a Fillomino Skyscrapers, or Tapa Skyscrapers, I wanted to try something new (at least, something I haven’t solved before). However, I liked the Tapa Skyscrapers idea as a base, so tried it on other genres. I eventually landed up on Pentominos. This seemed to work pretty well. The ending became a bit difficult but I think it goes smoothly enough.

As for the Sudoku, I was and still am pretty sad about needing the 4 digits But overall I guess it worked out well. I think the difficulty is around medium.

For 264 : Follow regular Sudoku rules. Additionally, each number in the grid represents the height of the skyscraper in each cell. The digits outside the grid indicate the number of skyscrapers seen from the corresponding direction.

For 265 : Place 12 different pentominos in the grid (as shown in the bank). Rotations and reflections are allowed. Pentominos can’t touch each other even diagonally, and cannot be placed on cells marked with “x”. Numbers outside the grid show the number of separate shaded-cell segments visible in that direction. A segment of length n, is taken as a skyscraper of height n. Skyscrapers of length n can block visibility of other skyscrapers of length n and below (which obviously means length n can repeat in a row/column).

P264

P265