The Sudoku playoffs featured Tiit Vunk, Jakub Ondrousek, Jan Mrozowski and Krystian Swiderski. Jakub Ondrousek finish first in the playoffs, followed by Krystian Swiderski, Tiit Vunk and Jan Mrozowski, making Krystian Swiderski the new Polish Sudoku champion. Full results can be found here.
The Puzzle playoffs featured Przemysław Dębiak, Matus Demiger, Zoltan Horvath and Tomasz Stróżak. The final results remained almost the same with Przemyslaw Dębiak finishing first, followed by Zoltan Horvath, Matus Demiger and Tomasz Stróżak. Full results can be found here.
I contributed a set for the Puzzle Championships for the individual round and wrote a team round together with Zoltan Horvath.
You can find all puzzles of the Championships in the following link: Sudoku Rounds + Team Round, Puzzle Rounds. My puzzle set is round 4. This post will feature all the puzzles from my individual round. Tomorrow I will post the Team round puzzles with a special surprise.
Last year's set was a bit on the difficult side, so I tried to think of a way to rectify that this year. I decided to write 2 puzzles per type, one smaller/easier one and a larger/harder one. I didn't want to make any too difficult. I selected 10 varying types of puzzles. I was hoping to average about 1.5 minutes per puzzle on the smaller ones and about 4.5 minutes per puzzle on the larger ones. I had the set tested by Prasanna Seshadri, James McGowan and Stefan Gaspar. The smaller puzzles made that average pretty well, but the larger puzzles were more inching towards 5-5.5 average and all of them had some outliers. I couldn't really decide well which puzzles to cut so I sent in the whole set and let them know that they could leave out a puzzle type if necessary. During their testing 3 of the larger puzzles seem to have cause some problems as they went up in score. I think the set will have worked well none-the-less for all solvers with the easier puzzles to work with as well, but I'd love to hear some feedback form those who were there.
Puzzles can be found below.
1. Anglers (15 + 35 points)
The smaller one is a really small and sweet puzzle. The larger one requires a bit of counting to get the larger numbers right, especially in the end. But it shouldn't cause too many problems.
Draw a line from each Fisherman (number) to a fish by moving horizontally and vertically form cell to cell. Each fish is caught by one fisherman. The numbers indicate the length of the line of the fisherman.
I like this genre, but hadn't done anything with it for a while. As it's not as common a genre, I figured I could make easier puzzles that would still take a bit more time to solve. The opening of the smaller one is easy, but one nice step in the middle. I am really happy with how the larger one turned out and think it's one of the better puzzles in the set.
Draw a single closed loop through the grid by connecting the centres of cell. The loop can't go through any cells with a bold black border. If such a cell is coloured black, it will be outside the loop; if such a cell is coloured white, it will be inside the loop. A number with a horizontal arrow indicates the number of horizontal line segments in the direction of the arrow; a number with a vertical arrow indicates the number of vertical line segments in the direction of the arrow.
3. Compass (35 + 50 points)
I like writing these puzzles. It sometimes gets a bit tricky to get them unique without ruining the solving path. I've seen some of Naoki Inaba's puzzles for Japanese competitions and they're generally a bit more tricky than mine and show well what can be done with it.
The small one is not too hard, but you have to know where to start. The larger one has an easier opening and shouldn't cause too much problems. I like how they both turned out.
Colour some squares so that all remaining white squares form a single contiguous polyomino. Black squares can't touch each other by a side. There can't be any 2x2 area of white cells anywhere. Squares with arrows or stars can't be coloured. Arrows indicate that this direction is the only way you can travel to the star over the white cells without backtracking.
4. Capsules (25 + 55 points)
I like puzzles with simple rules and this is a pretty simple number placement puzzle. I tried writing one for the championship last time, but that just tested horribly. So this time I made them with many more givens. Although the small one was too hard at first, so I rewrote it to this one.
Place the digits 1~5 once in every blackbordered region. No two equal digits can touch eachother, not even diagonally.
5. Star Battle (20 + 60 points)
Star Battle has become one of the standard genres and I like writing them. I couldn't really write an 8x8 puzzle for this genre as there are only two solutions for that grid size. So I wrote a very easy 10x10 puzzle instead. The easy one has 6 really quick placements, which gives you a lot to work with from the start. The harder one has a trickier opening to eliminate a few cells. After that it gets going.
Place 2 stars in every row, column and black bordered area. The stars can't touch eachother, not even diagonally.
6. Tapa (35 + 60 points)
I hadn't written any Tapa puzzles in a while. I tend to write less puzzles of types I have written many of before. I find it hard to think of fun new ways to start a puzzle. I have solved so many Tapas already with the TVC, CTC, Serkan Yurekli's Tapa book and the upcoming GM Puzzles book and all the others available online. But as it's become such an established genre I gave it another try. The small one was just all about interaction between adjacent clues. It took a while to get it correct, so that the middle turned out unique. It's one of the harder smaller puzzles in the set. The larger one was all about finding an opening. I don't normally put clues next to eachother much, so I gave that a try. Originally I was going to have 16 clue in squares, but there were just too many clues, so make the other two corners triangles instead.
Colour some cells to create a single contiguous shape. The shape can't have any 2 by 2 coloured areas. The clues in the grid tell you how many consecutive cells around it have to be coloured. If there's more than one digit in a cell, the groups of cells have to be separated by at least one empty cell. Cells with clues remain empty.
7. Pentopia (25 + 60 points)
This was the most successful creation for my LMI test. It's the only one I've really kept making. I think it works well in smaller sizes as well. I made these 10x10 and 12x12 as 12x12 is the normal size for pentomino placement puzzles. The two + clues set up the easy one really quickly. The larger one is a bit more tricky but at least has an easier opening.
Place pantominos in the grid without repeating any shape. Rotations and reflections are considered the same shape. The pentominos are not allowed to touch, not even at the corners. The lines in the grid indicate all direction(s) in which the pentominos is/are closest when looking from that square.
These were some of the first Araf's I had written. I was asked to write an Araf for the LMI Puzzle Marathon, but as I had never even attempted it, I wasn't sure how that would turn out. I normally go a bit too hard in my first puzzles, which isn't the best for marathon size. I rewrote both these puzzles, which you'd know if you'd been following my blog. The smaller one is not too hard. I'm a bit surprised with the points value. If you understand the rules, it should solve pretty quickly once you get the right pairings figured out. Most force themselves quickly though. The harder one has no bordering clues, which I thought worked out well. The opening is tricky, but should still be able to figured out logically.
Divide the grid into some regions, formed of adjacent squares. Each region should contain exactly two given numbers. The size of each region should be a value (in unit square) between the two numbers inside that region.
9. Hexa Skyscrapers (20 + 135 points)
I thought I should put in a type using a hexagonal grid. I hadn't written these before, but I think they turned out well. The smaller one was almost accidental. I put down the 2 clues to create an opening and then started solving to see where I needed to put down another clue. except that turned out to not be necessary. The larger one was the hardest puzzle in the set in my opinion. It took some time to create as I regularly ran into no solution. There's one tricky step in the opening, but seeing it will give you all fours quickly.
Place a digit 1-4 in some cells so that each digit appears once in each row and each diagonal line. Each digit represents a skyscraper of that height. Clues on the outside indicate how many digits are visible in that direction from that side. Larger digits hide behind smaller digits.
|Click to enlarge|
10. Nurikabe (20 + 135 points)
This was the last type I had added. I hadn't included a Nikoli type, so I figured I should included at least one. It should make the set more complete. The smaller one was an adjustment of the puzzle posted before. I was looking at it and went over it in my mind and thought that it seemed to be unique with pairs of 2's and 5's. So I jotted it on paper and checked and it worked. The larger one has a simple opening but the ending is quite tricky. It took me a while to draw up the last digits, which all turned out to be 3's to be unique.
Determine for each cell if it's part of the stream or an island. Each number is part of a single island of horizontally and vertically connected cells, which size is equal to that number. Islands can't touch eachother horizontally or vertically. The cells not part of an island form the stream. The stream is a single connected area, which doesn't cover any 2x2 areas anywhere.