Don't Let Your Snake Touch Itself!

[@richardstolk9815]

What an incredible joy seeing you solving this puzzle, exploring all the logic I’ve put in it. 😀 Well done! I intended to put in more negative constraints, but that didn’t turn out to be necessary.

[@yichen6313]

I love the puzzle!

[@tabularasa0606]

Beautiful, it was fun to watch Simon wiggle his way through.

[@buzzly108]

​@@tabularasa0606 Yeah this puzzle really tips the scales

[@davidhughes7174]

thanks Richard. I enjoyed watching your puzzle being solved

[@BozoTheBear]

A superb puzzle, just the kind I love, thanks!! Even though the rules are detailed, they're very interesting and natural. And the challenge of the puzzle is all about discovering the elegant logic, rather than finding some esoteric elimination (which you often find in difficult ordinary sudokus). Hats off!

[@sotek2784]

I love how the mistake he finds is not the mistake that broke anything, but backing up to it fixed the actual relevant mistake (the second 7 in r7c5)

[@Grikkez]

I was going to comment the same thing. As usual, if I watch a solve more than a couple of hours after the video comes out most of the mistakes I notice are already remarked upon in the comment section.

[@harryrandhawa21]

Yup i noticed that too..its look like a equation in math where negative multipled by negative results into postive answer..he did a mistake then did one more and get the right answer🤣🤣

[@brookead]

I was about to say the same thing! :)

[@margaretmcnarry4298]

Yes, I was yelling at him as he puzzled over his error!

[@jurgnobs1308]

he made another pretty big mistake but got lucky that it didnt matter

[@neodemonhawk]

23:56 That explanation is not why that doesn't work. The problem is you'd make R5C8 the centre of the palindrome forcing repeats inside box 6. The 3 in box 6 could actual be the middle digit and not require a partner at all.

[@sebastiahammer5771]

Yeah, it's because of the grey cell in box 4... it can't be 1 or 2! I was a little bit triggered

[@jeroensmulders1375]

Same here.

[@JackFlashTech]

@@sebastiahammer5771 oh, you’re right. I came to leave the same comment as @neodemonhawk, but I think you’re right.

[@SpencerTwiddy]

Was just about to comment this exact thing!

[@Mephistahpheles]

@@SpencerTwiddy Likewise....and did. I should read before commenting. Oh, well. And....@31:08, turns out there IS a 3 there. lol

[@Grikkez]

32:30 An easier way to see that the palindrome has a centre is to note that if it doesn't then two adjacent cells on the snake would have the same digit (and be in the same row or column).

[@gms8994]

"We don't want a very short snake, we need a lengthy snake" - She

[@asaenco]

I am having trouble concentrating on the puzzle, getting distracted by the inuendo

[@lucieea7544]

In the beginning i was looking for under 30mins long videos, and now i’m just so happy when i see that the video of the day is longer than 40 minutes

[@margaretmcnarry4298]

Every day I wait until evening and then choose the shorter video first so I can really enjoy the longer!

[@MatsLindgrenMusic]

MY ANACONDA DON'T MY ANACONDA DON'T MY ANACONDA DON'T touch itself because it's not allowed, apparently.

[@bobblebardsley]

Not even diagonally.

[@andrewbieny4564]

Also, never roll your snake. I learned a lot today.

[@philm5872]

My goodness..as I'm trying to solve this i find myself saying "now, can this square be snake? And the answer is NO!"..I've watched too much CTC!

[@tabularasa0606]

Impossible.

[@galxieranger8277]

Watched too much CTC? Bobbins! One can never watch too much CTC.

[@JohnADoe-pg1qk]

@@galxieranger8277 If someone finds you starved or died of thirst in front of the monitor, then you've watched too much CtC.

[@leximccarthy6347]

I find myself saying in my head “where does the 4 go in column 6?” And I know it’s because of Simon because it’s always in a British accent

[@mightworth3735]

You must be complete bonkers! Don't loop yourself in the phistomefel ring when you get cracking. It is dangerous when you lose self control and your eyes cannot brighten their surrounding lamplike - those two stars in a row. Can't we all agree that it was Mark who committed the murder?

[@rolfremie9634]

Word of the day! Quorate, meaning: having a sufficient number of officers or members present to transact business.

[@davidhughes7174]

knowledge bomb of the next order

[@justanothergamingyoutuber8179]

Idk man, pretty sure the word for day is day. And if you didnt mean it like that, I’m still quite sure that the day doesn’t speak either...

[@masheroz]

The meeting has a quorum. The meeting is quorate.

[@sanctionbuster]

44:21. Even as a Sudoku Padwan I was actively hunting for the negative constraint and was not disappointed to not need to rely on it. This is the best I've kept up with Simon EVER!

[@jamesandrewes9640]

1:22:35 without checking the video for hints. My most satisfying solo solve since I subscribed to this amazing channel!

[@conexant51]

According to a documentary I watched on National Geographic, in reality snakes actually enjoy a nice cozy cul de sac.

[@jmswtsn]

24:13 “assuming I trust my snake marks, and I think I should” 😂🤣 This whole puzzle was very entertaining to watch, for the solve, stumble, and the snake commentary.

[@chesshead]

23:28 "where does the '3' go in this box?" In the central cell, dead centre of the snake so it doesn't have to duplicate on the palindrome.

[@MrSolarin]

Yes, he missed that one. But if the central cell is the dead center of the snake, there will be twice the same number in box 6, because of the palindrome. So in the end he was right (but for wrong reasons).

[@brontesundstrom9288]

@@MrSolarin I didnt even think of that!

[@aravendad860]

Also if he went that way there would be no valid value for the grey cell in box 4 as 1and 2 were not allowed by sudoku and the snake would have at most 2 cells visible to it.

[@chesshead]

@@MrSolarin Ah yeah, I didn't see that.

[@charlesxaqairy709]

What's even funnier is that cell ended up being a 3 anyway.

[@thedrunkenelf]

Sudoku is FILTHY these days! What’s next? “Can’t wait to fill that box!”

[@maverickstclare3756]

A lengthy purple snake ! How did he keep a straight face

[@hammadniamatullah2297]

@@maverickstclare3756 The same way as whenever he finds naked singles

[@GSBrofly]

Don't let your snake touch itself

[@jameswiebe8956]

LOL. I was thinking along the same line. After the finding naked singles title, I was thinking that my snake shouldn't be touching itself anyway.

[@jeroenrl1438]

Luckily, naked singles are allowed to touch your snake.

[@Rangsk]

I found something pretty early on that really helped my solve on this one. From how Simon has the board around 15:30 you can make the following observations: 1) r7c3 must be a 6 just from the rules because it sees 6 snake cells. 2) This makes both 5s and 7s very restricted in box 7. They can't be in c1 because of the given 5 and 7 in the column, and they can't be the head of the snake because that would have the mirror into the other head which is impossible. So, 5 can only be in r7c2 or r8c3 and 7 can only be in r8c3 or r9c3. 3) With that marked, it's pretty easy to see that an 8 in r9c3 would force a 7 into r8c3 and a 5 into the grey cell in r7c2. 4) That 5 in the grey cell forces the snake to go down to r6c1 from its head in box 6, but the placed 7 in r8c3 would have to be mirrored there, which it can't because there's already a 7 in column 1. 5) This means r9c3 has to be a 7, finishing row 9 entirely and making the rest of the puzzle much easier.

[@SteveEdwardCooper]

When he put the 159 in the three squares in the top left box I started reacting as if a wide receiver was turned around and running the wrong way.

[@maaleru]

Palindrome snake must have a center. Basic sudoku rules can include 12321, but never 123321. Also it must be at the edge of box to turn.

[@andrewnelson2525]

So happy to see Simon stumble on this one -- because I did too and was quite annoyed with myself. The logic wasn't that difficult (I think Simon took the difficult path several times) but there was a lot of it and it was very easy to slip up and keep zipping along thinking you were golden when you weren't. Between the palindrome, snake logic, gray cells, AND sudoku, there was a lot to choose from at any given moment, which I liked a lot.

[@amoswittenbergsmusings]

A snake in the Garden of Eden Caused havoc - I wished that he didn’t. Thus all became rotten For Man had forgotten That touching oneself is forbidden.

[@roland9189]

Great Limerick, absolutely in style, especiall with the ending!

[@BillLamoreaux]

I recall Simon's comment from earlier this week "... and I always trust my pencil marks." ;-) Great puzzle!

[@OverkillSD]

A couple months ago, this would have taken me 3 hours instead of the 38:53 it took me today! Thanks for helping me sharpen my brain, Simon and Mark!

[@LednacekZ]

40:30 the mistake is in r7c5. you have 7 in the place of a 2.

[@Luxalpa]

So it was actually two mistakes!

[@MaartenKuif]

That's correct, Simon hadn't used the incorrect 159 triple to make any further deductions. The 7 in r7c5 was the actual mistake.

[@buzzly108]

Yes... I was disappointed he didn't notice that, but since he walked back the mistake in box 1, it ended up fixing itself.

[@RichSmith77]

A strange day indeed. Simon makes two mistakes. (Three, if you consider identifying the wrong mistake as the cause of his problems, as yet another mistake).

[@Raven-Creations]

I really enjoyed that. I think you made somewhat heavy work of it. By the time I'd completed the snake, I'd filled in almost all of the digits. Keeping on top of sudoko throughout the solve meant that a lot of the things you were straining at were easily solved. For instance, in box 9, there was a 12 pair and a 45 pair early on, which cut down the snake options around the intersection of boxes 1, 2, 4, and 5. That you managed to solve it as easily as you did, with one hand behind your back, is pretty impressive.

[@euanmcdougall1917]

At 28:48 There is a beautiful piece of logic The square Simon was looking at in R4C5 MUST be a 4. Because in the box 4 can't go anywhere else, by sudoku (via palindrome snake for R5C5) or in R5C6 because of the negative grey cell snake constraint!!! Amazing construction.

[@Gorfinhofin]

This is the first puzzle on the channel that I managed to complete without watching any of the video for hints. I loved it! I did take a little peek after I did the first part just to be sure I was on the right track, but that's it.

[@MrBrockarock]

exactly 30 minutes, this is the best I've done in a spacial combination puzzle so far, big fan of the palindrome border constraint. A ton of fun.

[@peterc.hayward8067]

40:33 for me! Beautiful puzzle, loved how the snake wasn't determined until right at the end.

[@kslingsby]

Lovely puzzle! And just as instructive watching how you get out of a mess as watching you getting it all right!

[@mafaldavanilla]

Been waiting for my daily dose of sudoku, and there it was when I opened youtube 😍

[@jerryjang]

20:27 you can find 12 pair and 45 pair in box 9, then you can use negative constraint for gray boxes to figure out the snake shape. Really enjoyed this one!

[@FoolishBubbles]

WOO! Just finished my first of these unusual Sudoku variants. Feeling very chuffed. It's about time after watching all of Simon's videos. Got it in 43:43

[@3possumsinatrenchcoat]

"We don't want a short snake" just once i want to see a solve where the maker has trolled and made the snake like 3 squares long. doesn't work with the "all grey squares are given" constraint, but still!

[@stevieinselby]

Completed in just over an hour ... not often that I can do these snake puzzles, so very happy with that ... it felt like more than a 3-star puzzle ... maybe that's because the threes were the keys to the snake ... I ended up by colouring in different pairs of 3s in different colours so I could keep track of which ones matched up with what.

[@eclectichoosier5474]

32 minutes! First time I've ever finished faster than Simon! (at around 38 1/2) (Of course, I wasn't explaining it as I went, so there is that. I'll take it!) Great puzzle!

[@m6novotny]

First one I've ever beat the time of the Simon or Mark! 30 minutes. Love these videos (and puzzles!)

[@imaginarycastle]

37:04 As soon as the whole snake path is determined, the negative constraint gives the 5 in box 2, which I found to be a quicker way to finish the palindrome. Beautiful puzzle!

[@BikerJack12345]

Nice puzzle. Just over 50 min to solve though. I disambiguated the snake in box nine by noticing that r8c7 and r7c8 were a 4-5 pair and that if r9c8 was snake, it would cause either the grey square in r7c8 or the not grey square in r8c7 to be broken.

[@mmmcounts]

Your lengthy purple snake mustn't touch itself en route to finding All the naked singles. Cheeky titles these days. I'd love to see a Kurthugoschneider song made entirely of titles of these puzzles and common sudoku phrases- including a puzzle or two of his own.

[@adnagapot]

This was so much fun watching your logic path going on here, really incredible

[@bakadude125]

Great puzzle! I solved the final part that Simon gets to at around 31 minutes in slightly differently, I used the negative constraint on the grey squares to determine the position of the 4 in Box 5, and thus the orientation of the snake in Box 9. The rest of the puzzle went on from there!

[@droraharon]

I love snake puzzles. Regarding the 3's possibilities at row 3, I actually reached the same conclusion, but quickly dismissed r3c7 as an option. It's true that the grey cell in r2c4 could be fulfilled, but there's a problem with the grey cell in r4c2 which has to be at least 3.

[@Tom__Cook_]

Took me over an hour but a really cool puzzle!! Congrats on 300k guys :)

[@jaeusa160]

@23:40 There was a much easier way to disambiguate those 3s on the snake. The grey cell in r4c2 still needs to find more snake or else it would be a solitary 1 and clash within the box. I believe r3c3 could've been colored as snake as soon as you colored r5c3 as non-snake since all possible patterns which touch r4c2 must proceed through that gate.

[@jcmono]

1 hour 3 minutes for me! Always pleased if I get it in less than double the video length

[@AdamRidley11]

If you remove the diagonal touching constraint you get a much harder puzzle that is still solvable up until finding the centre square which could take 1 of 2 positions. This could be made unique by stating that the centre of the snake doesn't touch itself diagonally. Then you'd have a really challenging puzzle that is great fun!

[@asaenco]

Loved this puzzle! Almost like doing two puzzles in one.

[@kenmolinaro]

The time he took to solve this was at least doubled by not noticing right away when he got that far, that the negative constraint on the 3 in r9c6 resolves the path the snake takes through box 9, which resolves the grey box at r7c8, which resolves the grey cells in box 7. From there, the path of the snake is trivial to work out.

[@gibbeldon]

Ah, the reference to the last snake puzzle, fabulous!

[@pumper2c052]

This was the first puzzle I did from your channel for myself I did it in 15 minutes I’m really good with numbers

[@amoswittenbergsmusings]

An amateur solver named Pritchett Discovered his grid’s final digit. He showed his euphoria By singing the Gloria With the lyrics “I finally did it!”

[@amoswittenbergsmusings]

Dear Simon with panache and dry wit Displayed - it is hard to describe it - His low-key expressions In all of his sessions: “You’ll *never* see anything like it!”

[@justanothergamingyoutuber8179]

* *claps* * ..how many of the comments did you make?

[@z-beeblebrox]

When he gives a Snake puzzle a go And it's time for a logical show He'll take a brief explanatory break And ask "now can this square be a snake?" Then the answer is always a "No!"

[@amoswittenbergsmusings]

@@z-beeblebrox An Internet surfer in Coventry Made while in his bath a discovery. He put down his flannel: “Eureka! A channel With numbers and words and bad poetry!”

[@amoswittenbergsmusings]

@@justanothergamingyoutuber8179 The ones in my name are mine;-) So is this: A poet who lived in the Highlands Made doggerels, not very good ones. When asked “Did you make them?” He said “I just fake them! Like the paintings I sold as true Rembrandts.”

[@jameswiebe8956]

That was a lot of fun to watch. I am really getting sold on using colour, but I see that I have got to start doing snake-type puzzles more. Figuring out the palindrome was "easy", but I had a heck of a time logicing (yeah, no such word, but you know what I mean) out the path of the snake so I could actually use the palindrome. 1 hour and 14 minutes.

[@HunterJE]

31:50 No need to re-count the whole palindrome to verify the midpoint, just counting the distance from each of the nearest pair of 3s would do since the midpoint of a palindrome is midway between *any* matched pair (e.g., in 1234321 the 3s are both one step away from the 4, the 2s are both two steps, etc)

[@magc_csgo7098]

Or even better: how would a snake that only moves vertically or horizontally work without a single-cell-center? It could never have a two-cell-center as those 2 digits would then always be in the same row or column.

[@HunterJE]

@@magc_csgo7098 Ahh clever point!

[@bristolrovers27]

Excellent puzzle 4 plus for difficulty

[@leoclimbing5624]

I did it after sooo many tries... Absolutely lovely

[@alibabapirce9782]

even tho you came to correct conclusion youre arguments were wrong in 23:30 . you see when you finish that snake way you did in that time the 3 in box 6 wouldnt be projected in box 2 because part of snake in box 6 is middle of snake (to be exact snake would have odd number of cells and middle would be in r5c8 and that middle could theoretically have 3 in it) the correct argument would be that snake has to go to cell in r3c3 because grey cell in r4c2 cant be lower than 3 and we can fill at max 2 cells from bottom of it and if so we need at least one more and to escape snake touching itself we have to go thru r3c3 cell which indeed is 3

[@rufioh]

I know Simon spends a few minutes explaining at the start, but I actually finished just before the video did. I feel great

[@jurgnobs1308]

damn, you actually made a pretty big logical error when placeing the 3 in the top left box. because just by logic of the palindromic snake, you absolutely COULD have put the missing 3 in the center of the center right box. because it would have been the exact center of the snake. the only reason the snake had to go left there was the grey square in the center left box (next to one of the starts of the snake) because that would only touch the snake either once or twice then, and 1 and 2 werent possible. so you actually got very lucky there that you picked the correct one despite your logic being wrong

[@Mujaki]

33:40 Schrödinger's Snake, in two quantum super-positions simultaneously. Until close observation collapses the waveform and gives a result.

[@bradstrickler]

I'm usually bad at these snakey puzzles, but i did this one without help in 30 min! Very proud of myself.

[@user84074]

20:12 Guards in Metal Gear when they see a box

[@doncook3690]

Another great puzzle. I wish it had negative constraints. Maybe a new standard rule set. Time to come up with fancy name for this rule set - maybe Slithering Mindfield. Hope it ends up in the book.

[@francoisduez601]

Approchable and very enjoyable, but I find it's easy to make mistakes!

[@dazzling_belgian]

70:27 but I'm proud of myself! The logic is amazing and the puzzle is really fun to solve. This palindrome constraint makes things interesting, I loved it.

[@Nyarlah]

37:38 for me, I loved it. I love this type of "spacial" puzzles.

[@Coyotek4]

27:10 One of my better solves. I'm definitely a fan of 'snake' puzzles. Nice puzzles!

[@ForeverDayGreen]

Wow thats an insane time. I took almost double that 😅

[@hess4win725]

What a fun puzzle!

[@alvaropallete]

45:34 for this incredible puzzle, I'm surprised that's very close to the length video, I usually take an hour or more for this kind of puzzles. PD: For a moment I worried because I thought I crashed it, for the cell in r4c3 which I marked as part of the snake and didn't correspond to the clue in r4c2.

[@yichen6313]

Really fun puzzle!

[@e7diablo]

He ends up getting to the right place, but 23:30 logic is wrong about where the 3 in box 6 goes because it could've gone in the central cell and been the middle of the palindrome (but as is otherwise pointed out, this path breaks the gray cell in box 4 so it still doesn't work). Just thought it was interesting that the logic that led him there was about the 3 but this specific step was wrong.

[@handuo6301]

okay.... this title is golden

[@Jessicaaljp]

2:53 for rules 4:22 for solve

[@juhaloukaja5078]

47:43. First time I've attempted one of these, very fun solve.

[@traisjames2]

I loved this one and the linking!

[@davidh.4944]

Aargh. This one took me forever. I broke it in the middle and had to start over _four_ times. No matter how careful I tried to be, I kept getting the logic of the snake path wrong (or something). 1h7m on my final run, but probably over five hours total. Still, it was fun, and extremely satisfying when I finally solved it.

[@kylescomments6033]

Is the logic at 23:30 flawed? When I was looking at it, it seemed like the 3 could go in the 14th position on the snake, which would be the center of the palindrome (27 digits long). It's true that the snake can't do this, which is easily seen by noting how the 13th and 15th position are in the same box, but I'm just wondering if the 3 logic was a blip, or if I'm missing something about it

[@HunterJE]

Yeah, I saw that too. Fortunately there's also a much simpler bit of logic that he actually already noted earlier that forces the snake to go the other way (the snake needs to switch back to revisit the grey in box 4 since it can't be 1 or 2)

[@StNeurion]

Yes, Simon forgets that the center cell of an odd palindrome doesn't require a mirror. He should have extrapolated the logic he was trying to follow at 12:00 to determine that there must be snake cells in Box 1 to satisfy the grey cell in r4c2 and therefore putting the palindromic 3 in column 7 would close the snake too soon.

[@RichSmith77]

Good spot. I missed it during my watch of the video. Simon mistakes the section of snake in box 6, between two 3s, as being the palindrome equivalent of the snake between the 3s in boxes 3 and 5. Too many 3s on his snake to keep track of. 🙂

[@QwDragon]

It would be cool to see something like that on programmers day in september. By the way, there was one more mistake after 159: at 39:16 box 8 needs 12 not 17 and it seems absolutely unrelated to 159 for me.

[@pink.arcanine369]

OMG I actually just done it in 26 minutes and beat Simon :)))

[@Nevir202]

Why not? NNN ended days ago. 🤣

[@HonkeyKongLive]

@Jaajgko things I never thought I'd see mentioned on this channel...

[@MRafas-ie9zh]

@@HonkeyKongLive I mean - look at the name of this video. Its not like he doesn't understand the implications of his phrases (especially when he grins all the time)

[@necaton]

now its DDD, right?

[@Nevir202]

@@necaton No idea what that would mean. 🤔

[@Nevir202]

@@MRafas-ie9zh exactly. Practically every time he says something about it you can see the “that’s what she said” level jokes passing through his brain 🤣

[@chrissolnordal9421]

A little under two hours for me, but I wasted about 30 minutes since I forgot the snake was a palindrome! However, that did mean I managed to work out a lot of the logic and constraints on the grey cells which was fun. Thanks to Richard Stolk, and of course to Simon.

[@markp7262]

34:57. Got stuck for a bit, went back and re-read the rules and noticed the negative constraint.

[@Felixkeeg]

23:36 also, if this was the right path, the grey cell in r4c2 had to be either 1 or 2, which are both impossible

[@Nevir202]

30:18 am I missing something? Why couldn’t the snake take r4,c3 enter box 1, staying away from the gray 6 then exit at the top and go on to take r2,c5 to get the 6 it needs? 🤔

[@MrSolarin]

If the snakes does that you only have 5 snake cells around the gray one, which is not allowed by the 5 in r6c4. And you can't do the same with r3c4 instead of r4c3 because the snake will touch itself diagonally (between r3c4 and r2c5).

[@Nevir202]

@@MrSolarin Damn, you’re right, I somehow miscounted that twice before posting 🤦‍♂️🤦‍♂️🤦‍♂️

[@adrianhead6272]

Don't ask how... but this seemed very straightforward - finished in 18m18s.

[@davidhughes7174]

1. You did make a boo boo 2. you are not an idiot. 3. thanks again for your wonderfull solve.

[@StrongStancer]

Took me only 21 minutes to solve, but I guess I was not 100% safe with my logic, as I sometimes assumed, that it can only work this way, without actually proving all other possibilities to not work. Stil very happy with my time^^

[@notchmath9642]

32:30 I mean if it didn’t have a center the two center squares would have to touch each other and be in the same row or column

[@wariolandgoldpiramid]

Oh snap, you're here too. You're everywhere!

[@notchmath9642]

@@wariolandgoldpiramid Damn! I feel the same about you and that one guy, Link to the Awesome or whoever

[@57thorns]

Any orthogonally connected palindrome has to be of odd length. Otherwise you would have two equal digits orthogonally connected.

[@Baer1990]

this puzzle brought me back to the minesweeper days :P

[@FrozenEmo]

The logic at 23:10 is incorrect, isn't it? The 3 between the other two could go into r5c8 and be the center of the snake. The problem would lie in r2c4 being a 1 and then no possible value for r4c2. Or am I mistaken?

[@Mitrasmit]

Funny how you fixed your 'real' mistake by correcting the 'harmless' one (and how you never spotted the real mistake, even during edit). You've made both mistakes independently of each other. The 5's you would have spotted when filling up. The 7 instead of the 2 would have been way harder to correct if you hadn't undoed everything.

[@SirCumference31]

What does “all possible grey cells are given” mean? I felt that how the grey cells works wasn’t properly explained at the beginning - Simon spent most of the time explaining what a palindrome is.

[@Wecoc1]

If a grey cell has a 2 it sees two cells with snake, if a white cell sees a 2 it DOESN'T see two cells with snake

[@craftypam9992]

Have you played Minesweeper? (Is it still available?!) The rule for the grey squares is pretty much the same: how many mines/snake squares do they touch?

[@maaleru]

If some cell sees 5 snake cells and contains 5, it must be grey.

[@adamheywood113]

"All possible grey cells are given" means that _only_ the grey cells have the property of seeing the same number of snake cells as the digit in the grey cell itself. There will be plenty of white cells that see snake cells, but the number of snake cells they see _cannot_ be the same number as the cell's digit, because then it would be grey. Take, for example, the white 2 in R5C7. If that cell touches snake cells at all, it cannot touch exactly two snake cells, because then it would be a grey cell.

[@luckymustard]

@@adamheywood113 How about rewording to this... Whenever the digit in a non-snake cell matches the amount of snake cells around it, only then are those non-snake cells colored in in gray.

[@DarrenNakamura]

Screwed up somewhere with my eights in the top right. Just going to watch the video for the solve now.

[@HalfBakedLunatic]

Wow! Incredibly good all the way around the snake :-)

[@zecatox]

14:15 > Interesting, I came to the same conclusion about this one not being part of the snake with a different logic : if it was, it would be the 5th cell from that end of the snake, yet the 5th cell from the other end can't be a 1, being in row 9 ^__^

[@Mephistahpheles]

@23:49 Ruled out that last 3 incorrectly. It COULD have been the very middle of the palindrome (with no partner 3) in R5C8. The grey cell in R4C2 needs another purple, though....so the snake has to turn left.

[@darrenhundt]

At 23:30 the 3 could be a single 3 as the center of an odd-length palindrome

[@Yamillplat]

very nice puzzle, i solved it in 67 minutes

[@maverickstclare3756]

What's funny is the mistake with the 159 wasn't what tripped up the snake, you thought the square needed to be an 8 when in fact it was a 79 pair already, you counted in the wrong direction along the snake :)

[@mauer1]

that beeing said, we probably done a million of those mistake and like backed up a million of times to never find anything remotly close to a solution of the problem ourselves.

[@Wecoc1]

Oof, you got me scared for a moment at the end 😅