Thursday 26 September 2013

TVC XVI Practise

Hello from Vancouver. Currently travelling before the WPC in Beijing. Need to be relaxed when I arrive there. Although maybe adding a small jetlag isn't totally the smartest thing. I was better located in Australia for that.

I wasn't sure if I could post any puzzles this week for the upcoming TVC XVI at Logic Master India.. I wrote a few puzzles on the plane, so I figure I'd share those. I hope they are of some use to people. Hopefully I will be able to compete in the last few days of the CTC and the last TVC. We will see. Everyone have fun at least.

There are four Tapas in this post.
The first puzzle is a Symmetric Tapa. This rule is very influential in the solve, so you really don't need many clues if you place your rectangles smartly. This one has four clues, but really shouldn't be that difficult a solve. I made it 11x11 as that way the rectangles would less likely share an edge if I placed all dots on grid points.
The second puzzle is a Toroidal Tapa. I like this variant. It's a bit trickier to design as you need to set a lot more blocks to make sure you can guide the wall where you want it to. I think this is a genre that can always use some practise, especially with looking around the edges of the grid. This puzzle is 12x12 as I liked this pattern of givens.
The third puzzle is a Transparent Tapa. This is the only genre that hasn't previously appeared on a TVC, so I figured I should at least make one of these. Although people can find a few of them on Prasanna Seshadri's blog. Oddly enough this rule change only means there is one clue that is invalid in normal Tapa. This one is also 12x12. I made an opening and then I noticed it would work more effectively in the corner of the grid. But to make a nice pattern of givens it would be better for the grid to be 12x12.
The fourth puzzle is a Alternative Tapa. This is the hardest of the four puzzles. This is not caused by the variant, as it's not overly influential in the solve. But the normal Tapa bit is pretty challenging and should give you all a bit of a challenge. Although maybe with the CTC you've had enough of those already. This one is 11x11 as it worked nicely with the TVC XVI pattern of letters.

Enjoy and have fun this weekend.

Puzzle can be found below.

Saturday 21 September 2013

Daily League Sudoku #30: Toroidal X-Sums Sudoku

This week a combination of two variants I like. X-Sums Sudoku is a genre that works really well with Jigsaw Sudoku, so I figured it would just as well work with Toroidal Sudoku. It's a bit tricky though as it's much easier to overlook that a certain digit already appears in a region. The puzzle is probably on the harder side, but I don't think any of the logic is overly hard. It's just tricky to keep track of everything with the Toroidal regions. I did add a few clues that aren't necessary for uniqueness. But there were clues planned there to keep the symmetry, but the puzzle proved to be unqiue without needing to put any there. They don't really ruin any of the logic, just create a few shortcuts.

Recap of the last Daily League week:
Sunday: Just One Cell Sudoku by Seungjae Kwak
Monday: Diagonally Non-Consecutive Sudoku by Karel Tesar
Tuesday: Arrow Sudoku by Prasanna Seshadri
Wednesday: Skyscraper Sudo-Kurve by Bastien Vial-Jaime
Thursday: Even-Odd Skyscraper Sudoku by Rishi Puri
Friday: Thermo Sudoku by Tom Collyer

Rules for Sudoku

In this Sudoku some of the regions wrap around the edge of the grid. Numbers on the outside indicate the sum of the first X digits in that row or column seen from that side. X is always the first digit in that row or column seen from that side.


Tuesday 17 September 2013

Czech Team Puzzle Championship

In the weekend of 7-8 September, the Czech Sudoku and Puzzle Teams Championships were held. The championship was held in Brno. The teams competed in a number of team and individual rounds over the weekend. The Sudoku event was won by the team of Michaela Bieliková, Matúš Demiger, Zuzana Hromcová and Jakub Ondroušek. The puzzle event was won by the Hungarian team of Zoltan Horvath, Pal Madarassy, Major Boglár and Zoltan Nemeth. Full results can be found here.
All Sudokus and puzzles of the championship can be found here. I also provided some of the Sudokus and puzzles for that event. This post will contain all my puzzles.
All my puzzles featured in a single round, together with 2 other puzzles. I hadn't written these puzzles to be a complete round and just wrote a number of different puzzles. It was Karel's idea to use them all together. I chose to write a number of common puzzle types, a number of uncommon and a number of variants of common types. So it's a good mix of puzzles to be featured in a single round. They are mostly puzzle types I had written before, so I knew what to do with them. I'm happy how they turned out and think it was a good mix of easy and hard puzzle.

Puzzles can be found below.

Czech Team Sudoku Championship

In the weekend of 7-8 September, the Czech Sudoku and Puzzle Teams Championships were held. The championship was held in Brno. The teams competed in a number of team and individual rounds over the weekend. The Sudoku event was won by the team of Michaela Bieliková, Matúš Demiger, Zuzana Hromcová and Jakub Ondroušek. The puzzle event was won by the Hungarian team of Zoltan Horvath, Pal Madarassy, Major Boglár and Zoltan Nemeth. Full results can be found here.
All Sudokus and puzzles of the championship can be found here. I also provided some of the Sudokus and puzzles for that event. This post will contain all my Sudokus.
This is the first time I actually provided Sudokus to a championship. Before the start of the Daily League I didn't really regularly write Sudokus. I think I'm getting a bit better on judging difficulty. I provided 3 easier and 3 harder puzzles. I also wrote an examples for each puzzle type. Two of the examples were also included in the championship. I think from the point values of the puzzles, my judgements of difficulty were pretty accurate.

Puzzles can be found below.

Saturday 14 September 2013

Daily League Sudoku #29: Different Difference Sudoku

I based this of a puzzle I've seen as an Instructionless Sudoku I've seen before. I don't remember where it was. As I remember it, it was a Sudoku, where in each nth nonet all differences n were marked (e.g. in nonet 1 all differences of 1, in nonet 2 all differences of 2). This puzzle has the same concept, that in each nonet all instances of a particular difference are marked. Except the differences aren't ordered and you have to figure out which nonet corresponds to which difference.
I hope the explanations of the rules are clear. If someone has a better way to formulate them, I'd appreciate it.
I think if you understand how the basics work, it shouldn't be too hard a puzzle. I've written better Sudokus and I think it can be done more elegantly. But overall I like how it turned out. I hope people enjoy it.

Recap of the last Daily League week:
Sunday: Anti-Diagonal Sudoku by Seungjae Kwak
Monday: No Point to Nine Sudoku by Jakub Hrazdira
Tuesday: Slot Machine Sudoku by Prasanna Seshadri
Wednesday: Figures Sudoku by Bastien Vial-Jaime
Thursday: Killer Sudoku by Rishi Puri
Friday: Diagonal Sudoku by Tom Collyer

Daily League PDF's:
Week 32
Week 33
Week 34

Rules for Sudoku

In this Sudoku, adjacent cells in a given 3x3 box containing numbers differing by n are marked. Adjacent cells with no marking must not contain numbers differing by n. The value of n is different for all 3x3 boxes. There is no restriction on adjacent cells contained in different 3x3 boxes.



Friday 13 September 2013

TVC XV Practise: Part 3ish

So, I tried today to make puzzles for the remaining three genres of TVC XV, but really nothing useful came out of it. A lot of tried openings, but in the end just a big mess of nothing useful came out of it. I could post something of the messy remnants of what were once good ideas, but I'm going I'm just going to repost the three old puzzles I have already linked in the Introduction. So for those who didn't bother clicking the many links in that post, you can at least get 3 nice puzzles to solve.
I hope everything still helped prepare people for the upcoming weekend. Enjoy and have fun.

Puzzles can be found below.

TVC XV Practise: Part 2

I was debating on whether to finish the other 3 types or posting these already, but figured I might as well post them now. I'm having some trouble designing certain variants. Both Double Back and Twopa are tricky to get right. The Twopa came together when I gave up on making the clue layout symmetric. It was just too much trouble. I will try to post the rest later today. I hope these puzzles are useful though.

The first puzzle is an Outside Tapa. I don't think this one is as nice as Serkan's puzzle from TVC VII but I think it's nice none-the-less. The variant isn't as influential in this puzzle, but has some points that should be important for the solve. But a few of the outside clues are purely to settle uniqueness.
The second puzzle is a Total False Tapa. This variant seems to always require a lot of clues. When I was done with the design I actually went out to edit the puzzle a bit, replacing multiple clues with 8's as the actual value of the clue was unnecessary, meaning that an 8 would work just as well. I think it makes the puzzle a bit nicer a solve. I think the end of the solve it trickiest.
The third Puzzle is a Twopa. It's a really tricky type to design, but I don't think the solve is particularly challenging. The main problem here is that you can't just add clues wherever you want as it might not work for both puzzles or it might not solve differently for both puzzles. But at least neither of the puzzles is solvable completely without solving the other grid.

Puzzles can be found below.

Wednesday 11 September 2013

TVC XV Practise: Part 1

Here are the first 4 practise puzzles for TVC XV. I will try to get the other 6 ready for tomorrow, but it can be that this week the practise puzzles come in three instalments. As always certain types cause more issues to construct than others. Especially the Twopa is pretty annoying to construct. I also had some trouble getting the No-Islands started, but I think that one turned out nice.

The first puzzle is a Hexa Tapa. I expect the puzzle in the contest to be a larger puzzle. I think in smaller size they really aren't generally very interesting, so I somewhat expect Serkan to go big and do something nice with it. I don't think this puzzle is too hard, but it isn't too bad. The two 1s on the outside were clues I'd have rather left out, but were necessary for uniqueness.
The second puzzle is a Tapa Skyscrapers. And I guess it's appropriate it's second as it's all 2s. I actually made the Kakuro-Style first and figured I could do the same with this genre. I think this one is the nicer of the two puzzles. It was at least fun to construct.
The third puzzle is a Kakuro-Style Tapa. It has the same inside clues as the Tapa Skyscrapers. I spend ages trying to construct this one, but I couldn't get it out the way I wanted it. People who are familiar with my constructing, know that I'm not all too happy with those 2 inside squares. I just liked how the opening worked and after many tries this was the nicest way to finish it.
The fourth puzzle is a No-Islands Tapa. I had some trouble getting this one started. It also took a little while to get all the constraints in correctly, so my first few tries I would realise too late that I had already broken a constraint or two. If you want to know which constraints, look a bit at the Cave/Corral/Bag genre; that should give you some ideas.

Puzzles can be found below.

Monday 9 September 2013

TVC XV Practise: Introduction

This weekend is TVC XV at Logicmasters India. It features five variants new to the TVC. The other five have appeared before. Many of the new variants have been posted on blogs before though. I will again try to write a practise puzzle for each variant. But here's again a collection of links to examples of these Tapa variants. If someone else knows of more exaples, feel free to add some links to them in the comments.

You will also again be able to vote for some of the variants which will appear in TVC XVI. I think this might be because some of the variants are getting a bit sketchy and Serkan wants to judge if people like the idea of certain variants or not in advance. Sometimes it's tricky to make a variant idea work, especially if you don't have any examples of it yet.
I would have found it interesting that TVC XVI would have featured a single variant as the main focus and make double variant puzzles. My best suggestion would have been Pata as that only changes what the clues indicate. So a Pata Islands or Pata Elimination is easily possible. I think that might be fun too.

Links to puzzles:

Tapa Regional:
http://mellowmelon.wordpress.com/2012/02/22/puzzle-389/
http://logicmastersindia.com/lmitests/?test=M201209P
http://puzzleparasite.blogspot.com.au/2013/08/tvc-xiv-practise-part-2.html
http://logicmastersindia.com/TVC/XIV/

Hexa Tapa:
http://oapc.wpc2009.org/archive.php?id=52
http://valezius.blogspot.com.au/2013/02/nr-992-hexa-tapa.html

Outside Tapa:
http://logicmastersindia.com/lmitests/?test=TVC8

Total False Tapa:
http://valezius.blogspot.com.au/2013/02/nr-989-total-false-tapa.html
http://logicmastersindia.com/TVC/IX/
http://logicmastersindia.com/TVC/X
http://puzzleparasite.blogspot.com.au/2012/02/tvc-ix-practise.html
http://puzzleparasite.blogspot.com.au/2012/02/tvc-x-practise.html

Tapa [Skyscrapers]:
http://yureklis.wordpress.com/2012/06/18/puzzle-28-tapa-skyscrapers/
http://prasannaseshadri.wordpress.com/2012/06/17/puzzle-no-172-tapa-skyscrapers/
http://prasannaseshadri.wordpress.com/2013/03/11/puzzle-no-316-336-polish-championship-set/

Tapa Doubleback:
http://puzzleparasite.blogspot.com.au/2011/12/puzzle-70-tapa-double-back.html
http://valezius.blogspot.com.au/2011/12/aa.html (without Tapa clues)
http://inabapuzzle.com/honkaku/disco.html (without Tapa clues)

Compass Tapa:
http://buyaketa.blogspot.com/2012/02/compass-tapa.html
http://mellowmelon.files.wordpress.com/2012/03/tvc12-practice.pdf
http://puzzleparasite.blogspot.com.au/2012/03/tvc-xii-practise-part-3.html
http://logicmastersindia.com/lmitests/?test=TVC12
http://yureklis.wordpress.com/2012/06/03/puzzle-10-compass-tapa/

Kakuro-Style Tapa:
http://anuragthefirst.blogspot.com.au/2012/09/kakuro-style-tapa_2575.html
http://anuragthefirst.blogspot.com.au/2012/09/kakuro-style-tapa_3.html

Twopa:
http://prasannaseshadri.wordpress.com/2012/03/30/puzzle-no-111-two-pa/
http://prasannaseshadri.wordpress.com/2012/04/01/puzzle-no-115-two-pa2/

Saturday 7 September 2013

Daily League Sudoku #28: Knight's Tour Sudoku

This week again an easier puzzle, at least it should be. I think the variant idea is pretty simple and might have been done before. I debated for a while whether or not to have the knights to move from a grey square to 1 through 9 and then back to a grey square, or to do it the way I did now. I thought this was a nicer way, as I thought the last move from 9 to a random number seemed a bit odd. The design was a bit tricky as it was easy to forget to check all numbers and whether it was still possible to connect the paths. The puzzle is fun although it didn't turn out completely the way I wanted. But as it had to also be a unique Sudoku, it worked out good. I only needed to give 12 clues, which I wasn't expecting. The pattern of 12 was the opening lay out, but I figured I would have to add some more to eventually get the Sudoku unique.
I hope you all enjoy it.

Recap of the Daily League:
Sunday: Average Sudoku by Seungjae Kwak
Monday: Poker Sudoku by Sina Hera
Tuesday: Palindrome Sudoku by Prasanna Seshadri
Wednesday: Little Killer Sudoku by Bastien Vial-Jaime
Thursday: Diagonal Sudoku by Rishi Puri
Friday: Outside Sudoku by Tom Collyer

Rules for Sudoku

In this Sudoku two knights are placed on a grey square with a digit 1. The knights then follow a path of knight's moves towards at least one of the other grey squares with a 9. The path travels through all digits 1 through 9 in order, including the digits in the grey squares. Each 9 should be reached by at least one knight.