Link to original post : Daily League Sudoku #42: Hit Sudoku

Last weekend was the Japanese NumberPlace Championship. It was full of great puzzles, but my favourite was the Hit NumberPlace by Naoki Inaba. I didn't manage to solve it during the championship as I didn't find the logic. But once I found the logic afterwards I really enjoyed it. That's why I decided to write one of my own for the league.

During the solve I realised a bit of logic that I thought would be fun to use in one of these puzzles. I just had to find a nice solution grid in which I could easily implement this. I actually stole a solution grid from the JNPC, which I slightly altered as at one point during construction I ran into no solution. But I noticed that by switching a few numbers around it could still have a solution. The trick I used isn't overly hard but I think it might be wise to try to solve the original puzzle first so that you can understand the logic involved, because I think it is useful to understand the genre before attempting this puzzle. The hit NumberPlace is #19 in the set.

That said, the puzzle is completely logically solvable. I think it is nice but it a bit on the harder side. Still, I hope you'll enjoy it.

Rules for Sudoku

Numbers outside the original grid indicate how many digits are the same in the solution grid in the corresponding row or column.








Posted in Daily League, Puzzle, Sudoku

Link to original post : Daily League Sudoku #43: Next To Nine Sudoku

Last Tuesday was the Dutch Sudoku Championship. I won the Dutch Championship and can now call myself Dutch Sudoku Champion for a year. The puzzles can be found at http://wcpn.nl. All Sudokus were written by Richard Stolk. In case you need the English translations for the instructions, they can be found in this forum post. This Sudoku was one of the types appearing the championship. I thought this was most likely the least common type to appear in the test, so that's why I decided to write one myself.
I think this puzzle isn't too hard, but I will await the times to see if my judgement is accurate. They are more often not correct when it comes to Sudokus. You can solve the puzzle at SudokuCup, which features all Daily League Sudokus suitable for the applet on a one day delay.

Rules for Sudoku

In this Sudoku, the digits on the outside indicate which digits are directly adjacent to the digit 9 in that row or column. The digits are not necessarily listed in order.





Posted in Daily League, Puzzle, Sudoku

Link to original post : Daily League Sudoku #44: Numpad Sudoku

Here is again a new variant, as far as I'm aware of. But if you really think about it, it's pretty similar to variants that have been used before. I think the tricky part is the fact that the horizontal and vertical rules aren't completely similar. The variant is based off the Numeric Keypad (or Numpad) you find on computer keyboards. On the off chance that someone is not familiar with its design, the given digits are in the design of one.
The puzzle has a narrow solve path through the opening, but finishes off pretty quickly towards the end. I hope it's enjoyable.

Rules for Sudoku

In this Sudoku a dot is given between 2 horizontally adjacent digits if they are horizontally adjacent on a Numeric Keypad. A dot is given between 2 vertically adjacent digits if they are vertically adjacent on a Numeric Keypad. All possible dots have been given.







Posted in Daily League, Puzzle, Sudoku

Link to original post : UKPA Open Team Round: Hole in the Wall

It's been a long time since I actually posted something. I haven't really gotten around to writing puzzles for my blog in ages. I took a break for a while. I have been getting back to writing puzzles a bit, but those have mostly been going out to other places. Some of them might appear again on this blog and others might be seen in other places online.

This post will contain puzzles I wrote as a team round for the UKPA Open. It wasn't an official round. It was more t give the puzzlers some practise in team solving while the organisers finished the final checking. I haven't much idea on the results. I wrote the round in two days and sent it in to Liane two days before the Championship was held; just in time for them to get it ready to be solved. I didn't have time to get it tested, but I hope people still enjoyed it.

The structure of the round is pretty simple. There are six 6 by 6 puzzles and six 10 by 10 puzzles. You are not given the rules of each specific puzzle, but are instead provided with six sets of rules under which each puzzle could be solved. You have to match the puzzles to the rules, so that each rule is used once for each size. Additionally, all 10 by 10 puzzles have a marked 6x6 hole, in which the clues of one of the 6 by 6 puzzles have to be placed, without reflection or rotation. Each 6 by 6 grid can only be placed in one of the 10 by 10 grids. The rules for 6 by 6 puzzle won't necessarily match the rules for the 10 by 10 puzzle it is placed in.

Puzzles found below or through the following link.

Read more »


Posted in Battleships, Corral, Four Winds, Island, Meander, Puzzle, Puzzle Championship, Shikaku, Special

Link to original post : 2014 Slovak Puzzle Championships

While going through my puzzle files, I came across the Slovak Championships folder. I realised I had never shared these puzzles on my blog. So I figured I might as well share them now.
I was contacted by Zuzanna Hromcova to write puzzles for their championship. We were given a number of categories to write puzzles in. One of the categories was non-grid puzzles, for which I provided three different genres; namely ABC Decoder, Dice and Mastermind. Dice and ABC Decoder are types I enjoy writing; Mastermind I didn't have that much experience with. But it was something I'd like to give a go.
The other categories I picked were Latin Squares and Division puzzles. For each type we had to write a standard genre and a variant on the genre. I picked Skyscrapers, with Haido as the variant. I like Skyscrapers and I thought Haido still had part of the Skyscraper logic, but used differently enough to make it not like solving four skyscraper puzzles.
For the Division set I picked ABCD Division, with Sum Division as the variant. It's a type I have seen a lot when I first started puzzling, but I haven't really seen it much since. I thought sums was an obvious variant, but I haven't really seen it this way much. I have seen a similar variant where the grid has to be divided into a complete set of pentominoes, but not really without this restriction.

I tried to put a bit of theming in the non-grid puzzles. I wrote a few nine digit ABC Decoders for the 2014 24 hour championships, and I thought that was a good size to use in a championship. The letters spell out THE SLOVAK, which was the nicest way I could use nine different letters to write something Slovakia related. I found some words with opposite meanings in the letter set, so I used those. I think it turned out well.
I used a similar opposites theme for the Dice puzzle, with an addition of 5 words to make it unique. I think not all words are necessary for uniqueness, but it solves pretty well this way.
The first Mastermind puzzle looks really nice, with a sequence of numbers and only white circles it solves really nicely. The second one was merely an attempt to construct a nice logical 5 digit puzzle.

I thought both Skyscrapers puzzles turned out nicely. The first puzzle uses three 4s and three 5s. The second puzzle has a trio of the same digit on each side. Of course I couldn't use four different digits as these are the only three digits you can have three of the same clue on the same side in this size.
I find it hard to theme Haido puzzles as the clues are a bit limited, but they both have nice logical paths.

The first time I saw an ABCD puzzle this way was at a Dutch championship. It was a bit of a surprise then. I wrote a similar puzzle for puzzlepicnic once and I thought it would be fun to include one for the championship. The ABCDE puzzle is a standard layout and I think it solves well.
The sum puzzles were a bit hard to work out openings at first as there are so many ways to reach the sums. So I went with obvious opening digits for both puzzles to then work back to more ambiguous digits towards the end. I think they both turned out well.

Puzzles can be found below.
Read more »


Posted in Dice, Division, Haido, Mastermind, Puzzle, Puzzle Championship, Skyscrapers, Word