Can You Become A Professor Of Sudoku?

*** TODAY'S PUZZLE ***
Maths Professor Dorlir has come up with an a blisteringly brilliant puzzle today - it's part sudoku and part fillomino... one difficulty the solver faces is that we aren't told which digits are which!! The whole thing is fascinating but take care - it is very easy to make a mistake!

Play the puzzle at the link below:

Rules:
Each digit from 1 to 8 must appear eight times in the grid. Some digits from 1 to 8 are sudoku digits and the others are omino digits. All instances of a particular digit are of the same type. For each digit, its type must be determined. A sudoku digit must appear exactly once in every row, column and box. An omino digit indicates the size of its omino (an omino is a group of orthogonally connected cells containing identical omino digits.) Two ominos of the same size may not touch each other - not even diagonally. For a digit in a circle, it indicates exactly how many circles contain that digit. Digits separated by a white dot are consecutive digits.

*** PATREON BONUSES ***
Simon's latest foray into the world of Islands Of Insight is available now!

They'll also be a bonus crossword video from Simon and his solve of Region Geometry by Emre Kolotoğlu (3hr 36min long...!) released over the weekend. And Simon's discussion video about Dean Mayer's Sunday Times crossword from last weekend will appear at 1minute past midnight on Sunday morning (which is the moment that competition has ended.)

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▶ Contents Of This Video ◀

0:00 Theme music & puzzle intro
1:26 Dungeons & Diagrams Stream last night
1:54 Islands of Insight & James Bond
2:24 Happy Birthdays
4:23 Rules
6:34 Start of Solve: Let's Get Cracking

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[dorlirahmeti]

That was impressive solve from start to finish, and enjoyed that a lot. I recently made my first Fillomino puzzle, and I was thinking lets do another one but I also wanted to do a Sudoku puzzle too, and then I said what if I do both at the same time, and after playing around for hours I managed to come up with this puzzle. It was definitely hard to make it but I was happy I pulled it off. I am really glad you loved it as well and you hit the most important steps as I planned. Thank you again for doing one of my puzzle it was pleasure, take care.

[Max-chov]

Discovered this channel a week ago, and now I am addicted. Great to see those videos really appreciate it. Big shout out to Simon from a viewer!

[mross]

Loving Simon giving a 5 minute explanation of factors of 8.

[jackbrowning]

the nearly 10 minutes of anticipation from 44:45 waiting for Simon to notice that 2 and 5 are not one digit apart is is kind of cathartic adrenaline rush I need to start my day.

[KrisCadwell]

1:15:00 I think the easier way to prove the nature of 2 is to look at box 3? (Left hand side, second from the top). 4 of the cells are already taken by omino digits, so there can be a maximum of 4 sudoku digits in the puzzle. Simon always finds a creative solution though.

[goldshield]

Dearest Simon,
I am a new addition to your subscriber pool.
Please know that when we shout at the screen because we see something you have overlooked, or even when we comment that the logic could have been seen quicker, it is because we stand on the shoulders of your giant logical brain. I could never have managed this puzzle in the ninety minutes that you managed, in fact, I doubt I could have broken in at all in my current capacity - perhaps one day after many years under your tutelage.
You are a fantastic logician and an amazing teacher. Thank you for your content.

[biligator]

This ruleset absolutely blew my mind. It's as if the omino and sudoku digits exist in separate universes of logic, but the circled digit device straddles the divide and makes them talk to each other.

[SVURulez]

Me watching this: "oh I got a deduction that Simon hasn't figured out yet, maybe I should try this puzzle myself." *5 seconds later* "...no I have no idea what's going on"

[kimbyd]

One shortcut I used was to realize that every row, column, and box had to contain the same number of sudoku and omino digits. So once Simon discovered four 8's in box 3, that proved that 2 was an omino digit. This insight helped a lot near the end of the solve to figure out the left side of the grid.

[martysears]

Great solve Simon, that was epic seeing you do battle with that. This was my first time seeing this puzzle, and I am again impressed not only at Dorlir's creativity at coming up with these concepts, but moreso at the masterful way he crafts the puzzle. This one kept being engaging right til the end. A beautiful use of counting circles too. I think the sudomino ruleset has some massive potential, if combined with other constraints instead of circles. Might even try one myself!

[kathrynbolle]

I always check the video length first and then do a happy dance when I see it's a long one!

[Mia-xscv]

Thank you so much for the birthday shout out, I really appreciate it! Looks like another great long solve, can't wait to watch. 😊

[MattYDdraig]

53:24
This is an obscene and wondrous marvel of puzzle building. A constant series of steps in the sudomino quicksand. Loved every second

[Trandhal]

the deduction starting at 36:24 I managed to figure out a full 10 minutes ahead of Simon, which is the only time through all the years of videos that I've managed to do so. It will probably never happen again

[davidrattner]

Constant joy to see such phenomenal setters create magic every day on this channel!! Then having Simon solve such magic as only he can with his aura and persona!!

[homewort-gfni]

For all the Simon maligns sudoku, he seemed to really struggle with not having full access to it in this puzzle, which did give me a chuckle! An easier, for me at least, way to see that 2 can't be a sudoku digit is as soon as you get 4 digits of 8 in box 3, you can't have any more than 4 sudoku digits, because you wouldn't be able to fit them in. You can make this deduction a little earlier than Simon does, because you know that the consecutive dot in box three must either be a 2, 3 pair, or a filimeno and a sudoku digit together, so as soon you rule out the three, you must have four filimeno digits in the box. I think the puzzle is a little easier if you focus on how many filimeno 'spaces' you have versus sudoku 'spaces'; almost like parity shading. Bravo Dorlir - wonderful puzzle!

[Raven-Creations]

This was a feast of logic. It was tough, but thoroughly enjoyable and one of the most amazing constructions I've seen.
The easier way to show that 4 is an omino is to consider C8. If it's a sudoku digit, the circles in that column must be 4567, making R6C8 45, and R6C7 is 3456. But, we know that all those are sudoku digits (if 4 is a sudoku digit), which all have to appear in the circles in that column.
@ 46:50 - You're musing about whether R5C8 is 1, 2, or 4. If you'd done the right thing and made the digit below it a 3 when you put 2 on the dot, you'd have realised that the remaining circles in the column had to be 567, so that cell you're considering must be 1. The cell next to the 2 can only be 1 or 2.
@ 50:46 - "So these squares are from 2, 4, 1, 3, and 5" - If you'd done sudoku, that run of three cells contains 3 and 5, only one of which can be on the dot. Therefore there is either a 3 or a 5 on the dot, neither of which can join with a 1. Also, R5C3 is 35, which means R4C4=8
@ 1:09:46 - You're dreading a comment about "at minute 1 you could have deduced that..." - not quite so bad, but at this point, how can 2 possibly be a sudoku digit? If it's a sudoku digit, it has to appear in every box, but box 3 has all of its cells allocated to other digits.
@ 1:30:01 - "So that means there is a 4 somehow affecting this area of the grid" - that was a really long way to deduce it. It's not possible to split up the circled 4s into two ominos, so there's a totally circled omino, and a totally uncircled omino. In box 1, you have to place a 3, 5, 6, and at least one 8 along with the 7 that's already placed. 4 cannot fit in the remaining three spaces. This means there must be at least two 4s in box 7.
I was surprised you didn't use star battles logic on the 1s - only one star can go in a 2x2. Once 1 was ruled out of box 7, and you had a maximum of five in the right half, R6C4 had to be 1, meaning there were two 8s in box 1, along with two 1s and the remaining sudoku digits.

[janeflett]

Wow, what an amazing puzzle. Filomino is really not my favourite but I liked this one

[ypsilonktze]

"We're positively in ballerina world up here, with two 2's appearing". Brilliant 😂

[troydunn]

Dang, Simon. Your brain is amazing.
Beautiful puzzle, but I had trouble keeping all the rules in my head at the same time.
Great puzzle. Great solve.