# Puzzle No. 380 : Outside-Consecutive Sudoku [Daily League]

I’m in a bit of a hurry today.

Recently, there was a Cubic variant from Bastien having Consecutive clues but no converse. And then, there was the Skyscrapers Kropki on Deception  that abandoned the converse part of the rules. I like this for its simplicity and the fact that it makes things easier aesthetically. Since I’m in a hurry, today seemed to be the perfect day to try and see just how simple it makes things to construct a Sudoku without the converse consecutive rules. I also like how Outside rules can work with it.

Rules – Follow regular Sudoku rules. Additionally, the digit outside must be placed in one of the first 3 cells in that direction. Also, if there is a dot in between 2 cells, those 2 cells must contain consecutive numbers. All dots are not given, so there is no converse rule.

Enjoy!

P380

# Puzzle No. 379 : Tapa

I really love using the 1-3 clue for Tapa. I’ve contributed a different 1-3 based puzzle elsewhere, and my birthday special was as good as a variation on including the clues 1-1, 1-3, 3-3. Here’s another much easier all 1-3 based puzzle. I made it for the local newspaper but thought the ending might be a bit much for beginners, so decided to post it here.

Rules for Tapa.

Enjoy!

P379

By Prasanna Seshadri Posted in Easy, Tapa

# Puzzle No. 378 : Arrow Sudoku [Daily League]

Firstly, Mathgrant, someone who I personally have had limited interactions with, but have a lot of respect for as a fellow author in the puzzle community, has fallen into some tough times. If you are feeling generous and want to give back to the puzzle community in some way for all the puzzles you’ve enjoyed solving (and if you’re new to his blog, you’ll find many more there), I suggest reading that post I’ve linked to and seeing whether you can help out. Also, my best wishes to Mathgrant hoping things get back to normal.

Now to today’s post.

If anyone is interested in contributing to the league, just join our facebook group and notify us that you’d like to. Otherwise, you can just join in and solve the rest of the Sudokus by top quality authors, and also discuss techniques and such.

Today’s Sudoku is an Arrow Sudoku. I’ve wondered why Arrow Sudokus generally have many givens whereas Killer Sudokus generally have no givens. I suppose its to do with the fact that digits are more difficult to force into an Arrow Sudoku without crowding arrows and making things messy. In this one, I tried to reduce the givens as much as possible while trying to preserve symmetry and not make the arrows crowd in the grid.

Difficulty wise, like the Yajilin in my previous post, this is probably not particularly hard by WPC standards but I’ll keep the rating anyway. I still think it has a few tricks that’ll make anyone pause and think though.

Rules – Follow regular Sudoku rules. Additionally, the number in a circle is the sum of the digits which are covered by its arrow. For circles with multiple arrows, apply the rule for each arrow separately.

Enjoy!

P378

# Puzzle No. 377 : Yajilin

Been such a long time since I posted a  (Non-regional) Yajilin. You’d have to go all the way back to my Polish set if I’m not mistaken.

Anyway, LMI hosts May Puzzle Test, Deception this weekend. It features some known, some not so common puzzle types with a little deceptive variation. The author is Ivan Koswara, better known as chaotic_iak.

Anyway, the puzzle below has a few places that’ll definitely need you to stop and think.

Rules for Yajilin. The blank gray cells are just clue cells without any numerical indication. The loop cannot pass through them and black cells can be adjacent to them.

Enjoy!

P377

# Puzzle No. 376 : All Even or All Odd Sudoku [Daily League]

Its been a mad, fun, exhausting 2 days. One evening with Manchester United Fan Club Mumbai at a screening of Sir Alex’s last home game in charge and also the trophy presentation. Full of mixed emotions but we made the most of enjoying the occasion. A day later, I was at the Wankhede stadium within shouting distance of the Hyderabad entrance, watching Pollard go on that six hitting spree in the IPL.

Anyway, back to today. You can download the league’s Week 16 PDF and Week 17 PDF.

Today’s Sudoku is pretty easy considering the things that can be done with this variant, but may still be a little challenging for first timers.

Rules – Follow regular Sudoku Rules. Additionally, in each 3×3 box, the shaded cells must be of the same parity, i.e., either they must all contain even digits or they must all contain odd digits.

Enjoy!

P376

# Puzzle No. 375 : Kurotto

Earlier this year, there was a contest on Tawan’s blog called Nikoli Hurdles. There were 8 Nikoli puzzles placed as hurdles for the participants, with the entrants who submitted all answers correctly then participating in an online randomized rock, paper, scissors game. The results of that are here. I received my prize a week ago now I think, and there’s 2 new-ish (I’d seen a few before the book, but not that many) genres on here, both of which I like. One of these is Kurotto. So I thought I’d create a Kurotto for the blog. I’ll let you be the judge of how good it is. On a difficulty scale here, it’d be a medium, but on Nikoli’s difficulty scale I see it being rated with a crying face.

Anyway,

Rules for Kurotto – Shade in some cells in the grid. Circled cells cannot be shaded. The number in a circle is the total number of shaded cells in the shaded cell groups that are orthogonally touching the circled cell. In other words, traveling through only shaded cells orthogonally, the circled cell must be able to reach as many shaded cells as its number indicates. Other instances of this puzzle have cells with blank circles too, which play no part except for being cells that can’t be shaded.

If that wasn’t clear or you want to see an example, here is the Nikoli version of the rules.

Enjoy!

P375

# Puzzle No. 374 : Odd Sudoku with Descriptive Pairs [Daily League]

Week 15 PDF.

Compared to how difficult Descriptive Pairs can usually get, I think the Odd part tames this combination a lot and puts it on the easy side. I still like how it turned out, especially with the clue pairs working out with a “same sum” theme that I was trying.

Rules – Follow regular Sudoku rules. Also, all shaded cells must contain odd digits. Additionally, for every pair of outside clues X and Y, at least one of these cases is true :

1) X is in the Yth position in that direction.

2) Y is in the Xth position in that direction.

Enjoy!

P374

# Puzzle No. 372 : Nurikabe [Windows]

Well, not exactly Windows. I’d made this variant in a slightly more restrictive way earlier which made it too easy, so wanted to use it a bit more this time. I wouldn’t call it difficult as such, there’s one tricky Nurikabe bit, and the rest goes smoothly enough.

Rules – Follow Nurikabe rules. Additionally, the 2 regions need to be negatives of each other. If a cell is determined as island part in one, its corresponding cell in the other region needs to be a stream part, and vice versa (rotations or reflections do not need to be considered).

Enjoy!

P372