Monday 31 December 2012

Puzzle #152: International Borders

Happy New Years India

As you might have noticed, this set contains far more new genres than my first set. I just wanted to avoid repeats of previous genres as much as possible. So I went on a long look through websites, looking for genres that might work with some of the numbers. From Palmer Mebane comes the puzzle type International Borders. During his LMI test, Puzzle Zoo, was the first time I came across it. I solved both of these puzzles during competition. I was hoping this genre would lend itself for a single digit puzzle, as it was different from most puzzle types. I first tried the number 0, but didn't like anything that came out of it, so I changed to the number 1. I found a simple opening and some interesting steps with only using 1's. I had to give in a bit to get it unique though. This isn't the best puzzle in the set, but I think it's still enjoyable. I might try this another time with more numbers, because it was pretty fun to try and design one of these.
It's probably and easy/medium puzzle. It might just take a while to get used to the genre.

1 - International Borders

Colour some squares without circles black, so that the grid is split into 2 seperate orthogonally connected areas. Circles of the same colour should be part of the same area, different colours should belong to different areas. Grey circles can be part of either area. Numbers in the grid indicate how many of the four orthogonally adjacent cells have to be coloured black. All black cells should share a border with both areas.

Puzzle #151: Sandwich

Happy New Years Indonesia and China

I went on the hunt for some puzzle genres I had never done for this set. One of the places this regularly leads me is of course Naoki Inaba's site. There seem to have been a few changes to his site. You can now copy all Japanese characters and some of the puzzle types have English translations added to it from the Naoki-Projekt on Logic Masters Deutschland. When I saw this type, I figured it could be a good genre to use the number 2 on. It took a while to get it unique. The opening is a bit standard, but in the end it gets a bit trickier, but there was no better way to force it unique. The name of the genre comes from google translate. It translated the puzzle name as "Santoitchi" but suggested I might mean the Japanese for Sandwich. It might have an alternative meaning but I got persuaded to just name it Sandwich. I have no real clue why it would called this though and I guess I could just stick with Santoitchi, as many Japanese puzzle types keep their original Japanese name.
The puzzle is medium/hard difficulty. There's a logic path to the end, but for a new genre it might be a bit trickier. It might help to try some of Naoki's at first.

2 - Sandwich

Colour some cells black, so that the remaining area can be split up into triminoes. No two black cells can share an edge. Each trimino must contain a number. A number indicates how many black cells share an edge with that trimino.


Puzzle #150: Lighthouses

Happy New Years Japan, South Korea and the rest of Australia

I tried a whole bunch of puzzle variants for the number 3. Slitherlink, Corral, Tren and Minesweeper were a few of the puzzle types. As I already had enough Loop Puzzles and not really any placement puzzles, I tried to find a genre that might work. Lighthouses was one of these puzzle types. The puzzle isn't very special, but I think it turned out okay.
This is an easy puzzle, probably the easiest in the set. Shouldn't take people too much time.

3 - Lighthouses

Place a number of 1 cell ships in the grid, so that no two ships touch eachother, not even diagonally. There are a few lighthouses in the grid. The lighthouses can see horizontallyand vertically. The numbers indicate how many ships can be seen in all four directions. No ships can touch the lighthouses, not even diagonally. Squares with water can't contain any ships.

Puzzle #149: Bosnian Road

Happy New Years Australia.

This is one of the new types to my blog in this set. I hadn't made any of these puzzles before this one. Again my first choice of digit worked out. I had seen Prasanna Seshadri make some good use of the number 4 in one of his puzzles, so figured this number might work. Took a while to get it right though as the number didn't let itself be unique that easily. It's the number which has the most possible configurations in this genre. It took a while to get the end right, but I thought the opening was really solid, so I wasn't going to give up on the opening and eventually i found a nice way to get it unique.
It's easy/medium difficulty. The opening is fairly standard, but it has a few trickier steps in the middle. Just for the fun of it, count the length of the loop in the end. It's purely coincidental, but I thought it was funny none-the-less.

4 - Bosnian Road

Draw a single closed  one-cell wide loop, that doesn't touch itself, not even diagonally. The loop doesn't go through clue cells. The clues indicate how many of the 8 cells around it are used by the loop

Puzzle #148: Tapa; Make Room for Pentapa

Happy New Years Samoa and New Zealand. 

The number 5 again had to be a pentomino puzzle for me. Last year's comined it with Nurikabe, where this puzzle combines it with Tapa. Other variants like Pentapa and Tapa Pentapool didn't really lend itself well for all 5 clues, but the added region constraint for Pentapa made it easier. I think it worked out well in the end and fits in well with the 5 theme this way.
This puzzle is again medium/hard. There's 2 important steps in the design, although the genre is pretty restrictive, so there might be other ways to the solution.

Rules for Tapa

Follow normal Tapa rules. Additionally, the Tapa wall is made up of 11 of the 12 pentominos (as the P-pentomino breaks a Tapa rule). Each blackbordered region contains exactly one pentomino.

Puzzle #147: All Seeing Snake

This puzzle came about after the For-Smarts Anniversary contest on LMI, where it was one of the puzzle types. I figured the rules had enough constraints to make a unique digit puzzle possible. As I needed a few puzzles with higher digits, I opted to try a puzzle with all 6 digits, as any higher would probably be too difficult. Played a bit with the grid sizes to see what would work best. Eventually this puzzle popped out. When I noticed it would have to be a 67 cell snake to make it unique, I opted to add an empty cell marked with an X, so the length would be 66 cells, as I thought that would fit in nicely with the 6 theme of the puzzle.
The puzzle is of medium/hard difficulty. Make sure to remember to make the Snake the right length.

6 - All Seeing Snake

Draw in the grid a snake of 66 cells. The body of the snake cannot touch itself, not even
diagonally. Numbers indicate how many segments of the snake are “seen” from this cell, not
counting the cell itself. Snake always makes a turn in the cells with numbers. The head and
the tail are not given and are subjects to determine. Cells with X remain empty.

Puzzle #146: Maxi Loop

This is one of my favourite puzzles in the set. I hadn't before made any Maxi Loop puzzles with larger cages, but I figured it was worth a shot. I chose 7 cells in 10 cell cages for my first try. I thought this would be the highest percentage of cells to be part of the clue to keep the puzzles interesting. If this wouldn't work out I always had the option to go 6 out of 10 or 7 out of 11. But tmy first try with this worked out really nicely. the solve is logical, but still challenging and I managed to get all cages to a 7.
I think this puzzle is a medium/hard difficulty, so it will probably take a bit more effort to solve. As always with a bit more unfamiliar genre, people might have some more trouble.

7 - Maxi Loop

Rules for Maxi Loop

Puzzle #145: Regional Yajilin

The higher numbers are always a bit trickier to find genres for. Last year's Island puzzle was a rare spark of genius as a choice, in my opinion. This year it's a Regional Yajilin. I spend a while looking for a good opening for this genre with the number 8. A few options didn't really lead to any good puzzles, but I think this one really worked very well.
I'm really happy with how it turned out. It's probably a bit challenging, because people aren't as used to how the black squares can be placed in this genre.

8 - Regional Yajilin

Rules for Regional Yajilin

Click to enlarge

Puzzle #144: Thermo Sudoku

The 9 was one of the tougher numbers to get a good genre for. I experimented with a few other genres, but many didn't work out. Some others worked better with other numbers, and I used those instead. Eventually I settled on a Sudoku as that seemed to work well with the number 7 last year. I used two 9 clues and part of the thermometers together form two 9's, so I think I put enough of the number in it, to warrant it a place in this countdown.
I think the puzzle turned out well. Not too hard, but some nice steps in there none-the-less.

9 - Thermo Sudoku

Rules for Sudoku

In this Sudoku, along a thermometer digits are always increasing, starting from the circle.

Puzzle #143: Sum Skyscrapers

This year we're starting the countdown with an easier puzzle than last year. The Killer Sudoku then was probably the hardest in the set. This time it's another sum variant, except this time it's a Skyscraper. This puzzle was again the first one I made. It was just one I made quickly about a month back and figured I should give this thing another go. I thought I might get things done in time this time, but in the end a lot of postponing and doubt on the genres to use, made me still trying to construct puzzles the last days before New Year's. I guess I work better with an imminent deadline.
The puzzle is easy/medium difficulty. Hope you enjoy it.

10 - Sum Skyscrapers

Rules for Skyscrapers

This skyscraper uses the digit 1~6. The numbers outside indicate the sum of the visible digits.

Sunday 30 December 2012

New Year's Countdown 2013

The end of the year always seems to be my least active period in posting puzzles. To make up for it there will be another puzzle countdown to New Year's. The concept will be the same. 11 puzzles between 12am CET December 31st and 12am CET January 1st 2013.
So if you have some time to pass till New Year's, check my blog during New Year's Eve. For everyone else, I hope they will be a good start to 2013.

Thursday 6 December 2012

Puzzle #142: Killer Sudoku

I've been a bit busy with other things, so hadn't had that much time to write puzzles for my blog. So here's a nice Killer Sudoku to pass the time. I wrote this one a while back but I think it's a nice one. I like Killer Sudokus without any 2 cell cages and this cage pattern works really well for such a puzzle. I hope you enjoy it.

Rules for Sudoku

In this Sudoku the given numbers are replaced by dashed cages. The number in the cage indicate the sum of the digits within that cage. Digits can't repeat within a cage.

Click to enlarge