Daily League #68: Inside Sudoku and Outside Sudoku

This is the second twin Sudoku. This time it's a combination of Inside and Outside Sudoku. They're pretty similar types, but the solve is still different.

Inside Sudoku first appeared on the US Sudoku Qualification. I thought the idea worked pretty well. I don't remember seeing it anywhere after that. I turned the idea in a Frame Sudoku, which has been repeated numerously, mostly by Richard Stolk.
The construction of the combination took a bit of work. Setting up the opening was pretty easy, but after that it gets a lot trickier. It's hard to pick the right digits that help both puzzles along. I liked the opening and found some points that nicely helped both puzzles along. It was hard to find a way to get both puzzles unique. There were a few situations that wouldn't resolve uniquely and I took a while to figure out how to avoid those.
I think both puzzles turned out nicely. The Outside Sudoku is the easier of the two. You get a lot of simple digits from the opening, while the Inside Sudoku's opening is more of a struggle. Enjoy.

Rules for Sudoku

Inside Sudoku: In this Sudoku digits on the outside indicate that these digits must appear in the 2nd, 3rd or 4th cell in that row or column when looking from that side.

Outside Sudoku: In this Sudoku digits on the outside indicate that these digits must appear in the first three cells in that row or column, when looking from that side.

Click to enlarge

Daily League #67: Edge Sums Sudoku and Frame Sudoku

Possibly this month will feature five Double Trouble Sudokus. I have written two so far, but I don't know if I will be able to write three others in combinations I haven't seen before. But I'm at least going to give it a try.

This week the puzzle can be solved both as an Edge Sums Sudoku and as a Frame Sudoku. I have used them together in a puzzle, but now they're separate puzzles. I tried for a while to get both puzzles to be solvable without any givens. I only had a limited range of sums to work with, which caused some issue. Edge Sums was the hardest to get unique in this combination as Frame Sudoku gives you the option of creating a useful implied sum. Eventually I compromised by putting two givens in the middle. The Edge Sums puzzle is the easier of the two in this set.

Rules for Sudoku

Edge Sums Sudoku:
In this Sudoku numbers on the outside indicate the sum of the first two digits in that row or column, when looking from that side.

Frame Sudoku:
In this Sudoku numbers on the outside indicate the sum of the first three digits in that row or column, when looking from that side.

Click to enlarge

Double Trouble #8: Skyscrapers and Haido

Haido is a puzzle type that I've recently come across a few times again. It showed up in a recent Skyscrapers contest hosted on Logic Masters Deutschland and the latest Akil Oyunlari magazine. All puzzles I've recently solved were really nice. So I tried making a few and found them more interesting to make than I at first thought they would be. When I saw the results, I thought they all look exactly like normal Skyscrapers puzzles. But they never solve uniquely as a skyscrapers puzzle. Usually they don't even have a valid solution.
So this led me to try to design one that worked as both. I found it hard to find an opening that worked nicely for both. so I cheated a bit with introducing a 6 clue for the skyscrapers puzzle, which is meaningless in the Haido puzzle. I like how they both turned out, although they are challenging.

Rules for Skyscrapers

Rules for Haido

Firstly this puzzle can be solved as a regular Skyscrapers puzzle. This is a hard puzzle.

Secondly it can be solved as a Haido puzzle. It is harder than the skyscrapers puzzle. I haven't solved any that are this difficult.

Double Trouble #7: Liar Loop and Maxi Loop

I guess this twin isn't very surprising. I did create the Liar Loop genre from the Maxi Loop genre. It has been the hardest one to acchieve so far though. I had attempted this a few times already, but it always lead nowhere. For this one I finally found a solid opening, that lead to good progress in both genres. Finishing it succesfully took some effort though. The puzzles both turned out well and I like the way clues keep helping in both genres.

Rules for Liar Loop

Rules for Maxi Loop

This puzzle can be solve as a Liar Loop puzzle. This one is the harder of the two puzzles. But that's mostly because Liar Loop is inheritently hard. It's a bit of a challenge to create really easy ones.
This puzzle can also be solved as a Maxi Loop puzzle. It's a bit easier than the Liar Loop puzzle. Main reason for this, is that I couldn't avoid using 1 clues for the Liar Loop puzzle.

Double Trouble #6: Heyawake (wacky) and Regional Yajilin

It's been a while since I have done one of these. I had been trying to play around with Ripple Effect/Heyawake and Ripple Effect/Regional Yajilin, except those never came off the ground much. It didn't feel that nice as I had to overload the Ripple Effect puzzles with uneccesary clues to get the other puzzles unique. So I thought that maybe Heyawake and Regional Yajilin might work as they can have a comparable amount of necessary clues. I found it a bit hard to make it work with rectangular regions, so I gave irregular reginos a try and that turned out a lot better. They're both not the hardest puzzles, but I like how they turned out.

Rules for Heyawake

Rules for Regional Yajilin

So firstly this puzzle have be solved as a Heyawake (wacky) puzzle. Opposed to normal Heyawake the puzzle has irregular rooms. The white area still can't span over two or more boundaries, even if they belong to the same room. This one is probably the easiest Heyawake on my blog.
Secondly it can be solved as a Regional Yajilin puzzle. It's not too hard, but it has some trickier steps than the Heyawake, but these are more because of the genre type.

Double Trouble #5: Slitherlink and Turning Fences

This combination of puzzles took the longest to get to work out of all Double Troubles so far. I couldn't get the end to work for most my tries. Maybe it didn't help that I was stubborn in wanting to use a preset layout. It's easier if I just place clues where they are needed.
These Turning Fences I haven't really seen many of. The only time that really comes to mind is a WPC. I'm thinking it was in Borovets, but not too sure. I just came to use it again recently and I figured it should be possible to make them looking like normal Slitherlink, so figured it might also be possible for one to actually be a Slitherlink.

Rules for Slitherlink

Rules for Turning Fences

So firstly it can be solved as a Slitherlink puzzle. this puzzle has its easy and hard parts.It still seems pretty typical for the style and difficulty I like to make them.
Secondly it can be solved as a Turning Fences puzzle. This one is about the same difficulty as the Slitherlink puzzle but as its the first on this blog it might feel harder.

Double Trouble #4: Tapa and Pata

So this idea started with an opening that worked very nicely for both puzzle types. So I really wanted it to work out. It took a lot of effort though to get it to fall. The two types block eachother a bit. I've always liked Pata. It's probably my favourite Tapa variation.
On an unrelated note, I've edited Puzzle #21. Due to my natural curiosity and excellent understanding of Japanese (or google translate working well enough to understand what was being said) I found out it wasn't unique.

Rules for Tapa

Firstly it can solved as a regular Tapa puzzle. I think it's a nice puzzle.
Secondly it can be solved as a Pata puzzle. Here the clues indicate the groups of connected white cells that are around the square. Different groups of white cells are seperated by at least one coloured cell. This one worked out nicely too.

Double Trouble #3: Easy as ABC and Skyscrapers

So this post will have 2 grids and 4 puzzles. This is somewhat the logical extension as the 2 genres don't actually normally look alike. Skyscrapers uses numbers and Easy as ABC uses letters. Still, they are somewhat similar as they both use clues indicating sight from the outside for a particular row or column. So there will be a grid that looks like a Skyscraper but is both and a grid that look like an Easy as ABC puzzle, but is both.

Rules for Skyscrapers

Rules for Easy as ABC

Skyscrapers Lookalike

This puzzle solves as a regular Skyscraper with digits 1-6. It's quite a tough puzzle.

This puzzle also solve as an Easy as ABC puzzle, but instead of letters you fill in the digits 1-4 in each row and column.

Easy as ABC Lookalike

This puzzle solves as a regular Easy as ABC puzzle, with letters A-D.
It also solves as a Cryptic Skyscrapers puzzle with digits 1-6. Each letter stands for a different number and all occurences of a particular letter are the same number. This one is also the harder of the 2 puzzles.

Double Trouble #2: Country Road and Ripple Effect

Here is number two. I was happy this worked. I'm hoping people are surprised this was possible as the 2 genres aren't even close to having the same rules. This one did cause me a lot of trouble creating in the first few tries. Both puzzle types have their uniqueness issues and they are not really always fixable in the same way while keeping the design. But it worked out in the end, keeping the designed paths nicely

Rules for Country Road

Rules for Ripple Effect

Firstly the puzzle can be solved as a Country Road puzzle. I don't think it's too hard, but there might be some struggling points in the middle.
Secondly it can be solved as a Ripple Effect puzzle. This puzzle is a bit harder especially towards the end.

Double Trouble #1: Slitherlink and Toroidal Slitherlink

I've always been interested in puzzles that can be solved under 2 different rules. It won't be a regular feature as I don't think I can pull it off every time I try. It's just something I find interesting and sometimes give a go. There's a lot of puzzle types out there that look the same at first sight, so there's enough options for me to try it with.

Rules for Slitherlink

This time it's two slitherlinks. You can solve this puzzle as a regular Slitherlink puzzle. It's not too difficult, but still fun.
You can also solve it as a Toroidal Slitherlink. Here the edges of the grid wrap around on eachother, which turns opposite edges of dots into the same line. This means the loop can run from one edge and continue on the other side.
Not every puzzle type will give the possibility to create a puzzle that is both regular and toroidal. This one works as in runs over the grid lines.