Puzzle No. 511: Arrow + Between 1 & 9 Sudoku

I want to call the variant a lot of people now know as “Sandwich” by what it used to be called, including in past posts on this very blog. This is a puzzle I’d worked on a while back, for a speedsetting contest that I was too late to submit to.

In other news, the WPF Sudoku Grand Prix final results are here – https://gp.worldpuzzle.org/content/wpf-gp-sudoku-results-2021

There could be a minor change or two since the round 8 results are still “preliminary” but I’m confident that my final placement won’t change. So I’m 6th! Considering I started the year targeting a top 10 finish, I’m pretty happy with this. I had a really strong finish in the last 2 rounds.

What else.. oh ya, I just wanted to note that this is the vague schedule I’ll be going for (every alternate day). I’ll branch out on topics as I go I think.

Rules –

Insert a digit from 1 to 9 into each cell so that no digit repeats in any row, column, or bold region.

Additionally, the number in a circle is the sum of the digits which are covered by its arrow. Digits may repeat along arrows.

Also, the clues outside the grid are the sum of the numbers that are between the digits 1 and 9 in that row or column.

Penpa link to solve: https://git.io/JBj0a (You can tab with surface and Sudoku, the answer check is just for correct digits)

Some solving steps for Puzzle 499, a bit about LMI, and some other stuff

I am attaching a mini-walkthrough PDF for the Arrow Sudoku I posted for the league recently. Its a bit rushed, and only takes the solve through the more difficult deductions, but should be really helpful if you were stuck on that Arrow Sudoku or didn’t attempt it but want to know more about the variant in general. Here’s the PDF –

P499

Now, a bit of a plug. Want more walkthroughs? We do much more detailed ones for LMI patrons. Also, I should say that, at least currently, supporting LMI would mean you are supporting my personal goals too (which is why I don’t have any such effort for this blog).

Also, I might have to disappoint any fans of milestone puzzles by saying that I currently don’t have anything planned. But you never know right? Maybe I think of something worthwhile in the next few days. If I don’t, then come Saturday I’ll just post a League Sudoku as my 500th and that’ll be that.

Soon I’ll be shifting residence, so I’m generally a bit more busy since I want to finish a bunch of things before I probably lose internet access for a week or two.

Puzzle No. 499 – Arrow Sudoku [Daily League]

This puzzle has a nice application of group-thinking… I think. The solving path is also pretty narrow. Not something I’d advise for beginners.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

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.

Rated – Hard.

Enjoy!

P499

Puzzle No. 495 : Arrow Sudoku [Daily League]

Update: Puzzle had 2 solutions. Fixed now. Apologies.

Just about got in a Wednesday post.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

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, where some arrows can have some cells in common. (e.g., 1-2-3 and 1-2-1-2 are valid sums for a 6 in a circle, with the starting 1-2 being common).

Enjoy!

P495

Puzzle No. 483 – Arrow Sudoku [Daily League] + updates

A few things –

If you haven’t already, please like/tweet/comment for my blog here (if you like my puzzles of course). The blogging awards will be handed out in a public ceremony on the 9th of February (you can find out from the link how to attend if you want to) and some publicity for what we do is always a good thing.

The blog will now be divided into 3 main tags.

1 – Daily League – Medium to difficult mostly-variant Sudokus.

2 – Ex-Contest – Although I won’t be releasing everything I contribute to Championships free anymore (more on that later), I’ll release some of the smaller doses, like when it’s not enough puzzles to make up an entire set.

3. Instructive – I am working on a curriculum for puzzles, and as a result, I feel the need to put some easy puzzles and some preview of tips and so on, without giving the entire content away of course.

I will be linking to this post in the future for reference about the tags. Hopefully I’ll post 2 and 3 tomorrow and day after itself to give a full view of the plan going forward, but can’t be sure of that as I have travel coming up. Definitely within the week.

Now to to the Daily League.

First, PDFs!

The League of Extraordinary Ladies and Gentleman_week01_2014

The League of Extraordinary Ladies and Gentleman_week02_2014

The League of Extraordinary Ladies and Gentleman_week03_2014

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay.

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!

P483

Puzzle No. 439 : Arrow Sudoku [Daily League]

I’ll be posting about a Championship and my puzzles in it tomorrow. For now, I didn’t want to crowd up this post.

Remember that you can solve the puzzles from the League online on the Sudokucup Guest League page with a 24h delay. Speaking of Sudokucup, much thanks to Karel for providing this version of the image, with the arrowhead present in the circle. I think it provides more clarity than the version I had drawn up before it.

Today’s Sudoku was quickly put together because I couldn’t really get much time to think for it. That, in general, seems to be a good thing, because I always over-think things these days when it comes to picking variants/puzzles/themes that I want to do. Not sure why thats happening now.

Anyway,

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.

Rated – Medium (I think). 

Enjoy!

P439

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