New Ideas In Killer Sudoku
Vložit
- čas přidán 11. 06. 2024
- ** THE SUDOKU EVENT OF THE YEAR **
Huge news: Phistomefel's first ever sudoku hunt will DEFINITELY BE ARRIVING BEFORE CHRISTMAS!!! We're gifting this to all our patrons to say "Thank you" for supporting us.
/ crackingthecryptic
** TODAY'S PUZZLE **
A stunning sequel today from Cane_Puzzles - the 14 year old genius from Turkey! This one is (sort of) approachable and you'll be amazed at what new logic emerges from the world of Killer Sudoku!!
Play it at the link below:
app.crackingthecryptic.com/su...
Rules:
Normal sudoku rules apply. (ie place the digits 1-9 once each into every row, column & 3x3 box). In cages, digits must sum to the small clue in the top left corner of the cage. Digits cannot repeat within a cage.
** NEW CONTENT ON PATREON **
As well as the incoming Phistomefel extravaganza, Simon's solve of tallcat's Shadow is now available - if you want to try the puzzle (which is a mind-melter) then check it out at this link:
logic-masters.de/Raetselporta...
Joining us on Patreon costs as little as $2 a month.
We've released our December monthly reward - The
Cryptic Scriptures Of The Secret Snake Society - a sudoku hunt featuring nearly 20 puzzles by some of the greatest setters on the planet. Anyone who solves them all by 20th Decmber gets shoutout! Remember that patrons gets access to their own special channel on the CtC Fan Discord server - where you can find hints ;)
/ crackingthecryptic
** NEW GAS PACK IS OUT **
The new GAS pack is out on Steam for PC here:
store.steampowered.com/app/21...
It's already out on Android and App Store. 60 original puzzles by Sam Cappleman-Lynes, Clover and Philip Newman!! Earn party hats and dinosaurs with these brand new puzzles!
We've also released a FREE app full of handmade puzzles to celebrate reaching 500k subscribers - simply download the Cracking The Cryptic app on Android, Steam or App Store and then select the 500k pack. We're streaming a playthrough of this app and you can watch all seven episodes
▶ Contact Us ◀
Twitter: @Cracking The Cryptic
email: crackingthecryptic@gmail.com
Our PO Box address:
Simon Anthony & Mark Goodliffe
Box 102
56 Gloucester Road
London
SW7 4UB
(Please note to use our real names rather than 'Cracking The Cryptic'.)
▶ SUDOKU PAD - Our New App ◀
You can input classic sudoku puzzles into our software and help support Sven, the programmer responsible for the wonderful user interface we all use to play these puzzles everyday. The app also comes with 12 handmade puzzles from us:
iOS:
apps.apple.com/us/app/svens-s...
Steam: store.steampowered.com/app/17...
Android:
play.google.com/store/apps/de...
ALSO on Amazon: Search for “SudokuPad”
**************************************************************
▶ CTC FAN DISCORD SERVER◀
/ discord
▶ OUR BACK CATALOGUE - ALL CATEGORISED WITH LINKS!◀
tinyurl.com/CTCCatalogue
▶ NEW CRACKING THE CRYPTIC MERCHANDISE◀
teespring.com/en-GB/stores/cr...
▶SEND US PUZZLES TO SOLVE/CONTACT US◀
crackingthecryptic@gmail.com
▶FOLLOW US◀
Twitter: #crypticcracking
@crypticcracking
Instagram (for how to solve daily clues from The Times): crackingthe... - Zábava
I looked up the 14 year old setter for this puzzle, and he recently won silver at the World Sudoku Championships for Under 18s. He was interviewed in Turkish media and talks about this channel and says he even got to meet Mark in person! Glad I'm not the only Turk hanging around these waters! Congratulations again to Can.
The mathematical principle that tells you that an 8 and 9 must be in a cage together in columns 4 and 5 is called the "pigeonhole principle."
Interesting: en.wikipedia.org/wiki/Pigeonhole_principle
I feel like ever since Simon started singing about 3's in the corners, setters have placed a disproportionate number of them there on purpose and I know I'm always hoping for one - and that Mark & Simon will notice it.
Three in the corner appears in 34/81 of valid Sudoku grids (I asked the question on the Discord server a few months back, and we ended up with three ways of getting the same result). So 3 Is naturally in the corner of a little more than 40% of randomly selected Sudoku grids (it is less than 4/9 because there are grids with three in two corners, but the same digit can never be in three corners of the same grid). In Simon's "should you guess" solve a couple of days ago the setter could have put three in the corner (reversing the inequality sign does that) but didn't notice. Nor did I when I tested it - and I have set "three in/not in the corner" puzzles - check out "Three in the spotlight" or "Game, set and no three in the corner" on LMD (the latter is pure killer, with interesting logic - the first is also a killer with some extra clues). There may be a minor tendency - but the "three not in the corner" effect is also dramatic. Perhaps there are channel statisticians who will monitor this trend along with the others which get routinely examined.
My personal calculation is the probability space includes:
- 2/9 for row 1 having 3 in the corner, end there
- 7/9 for row 1 not having that. In that case:
---- row 9 has a 2/(9-1)=1/4 chance that 3 is in the corner ( the -1 comes from the 3 in r1 blocking one of the middle spaces in r9 from having a spot), giving a total probability of 7/36 for this case
The overall probability of 3 in the corner is hence 2/9 + 7/36 = 15/36 = 5/12.
The differenc between the two calculations is less than 1%, with my 5/12 probability underestimating the probability of 34/81. I'd like to know where I might be going wrong, if there's a factor in the second case that should be different.
@@minamagdy4126 The calculation goes like this. 1/9 of all grids have 3 in r1c1. Then, because fixing r1c1 still allows r789 and c789 to be permuted freely, so there is a 3 in r9c9 1/9 of the time (there are 36 possible permutations of the last three rows and the last three columns, four of which put 3 in the corner: 4/36 = 1/9). This gives 8/81 for 3 in r1c1 and not in r9c9 and 1/81 for 3 in both r1c1 and r9c9. Similarly there is 8/81 for 3 in r9c9 and not r1c1, making 17/81 for 3 in one of the corners of the negative diagonal. If 3 is in a negative diagonal corner it is excluded from either corner on the positive diagonal, so the two diagonals are mutually exclusive and we get another 17/81 on the positive diagonal making 34/81 altogether. There are various ways of counting. The probability of a particular number in the corner of an n x n grid with at least one horizontal division and at least one vertical division (this condition makes it possible to permute opposite corner boxes independently of one another, so the same argument works) is (4n-2)/n^2.
@@minamagdy4126 On your calculation, having placed 3 in row 1, there are 8 places in row 9, it is true, but I don't think it is true that they are all equally likely. The 3 in the top row eliminates 3 positions for 3 in the boxes below it. There are four positions for 3 not in the corner in row 1 in boxes 1 and 3 and three in box 2. When there is a 3 in row 1 box 1 or box 3 there is a higher probability of 3 in the corner (1/6) in the box below than if there were a 3 r1 box 2 (1/9 for both bottom corner boxes).
@@markbennet9058 boxes! Of course it was boxes. It seems I've naïvely calculated the probability for a latin square, rather than a sudoku.
Thanks Simon for giving us our daily dose of cracking the cryptic
Can’t really complain that this video is 12 minutes late when yesterday’s was 90 minutes early. 😀
I love when he's doing Sudoku and has his cursor on a square where a number can be placed as the 3 in box 2.
Simon surprised that sudoku helps him... when he usually ignores it. And then just after ignoring the sudoku again and getting stuck.
Oooo! When you accidentally clicked tick it came up with BOBBINS! That's cool!
27:20 Simon just being Simon and repeatedly ignoring the killer cage in box 7
Simon & Mark, thanks for keeping up the twice daily puzzles. I appreciate that dedication.
In case you're wondering why the setter didn't use all 7 different Tetris pieces in the stack: this turns out to be impossible using a simple checkerboard parity argument 😄
This is one of those puzzles that I just throw my hands up and watch Simon do it.
That’s such a pretty puzzle!! Wonderful sequel. The fact that those right-side cages are deducible is incredible to me
Actually successfully solved it without the video! I had to write total notes in the cells and nearly made one of the cages only add up to 19, but I managed in the end!
I watch from China too, and you're right - you can't really watch youtube here... but vpn's are a gift from the internet gods.
I had a different way to get the contents of the three 20 cages in c4 and c5, using parity.
There are four even digits per column, so eight in total for c4 and c5. Having reached Simon's position at 11:50, with the 2-4 pencil marked in c4, that's four of the even digits accounted for. Every 20 cage has to have an even number of even/odd digits, so 0, 2 or 4 even digits. Since we only have four even digits to distribute between the three 20 cages in c4 and c5, one of these cages has to have zero even digits, i.e. it has to be all odd digits. Since the five odd digits sum to 25, the one missing odd digit has to be 5. Therefore one of the cages has to be {1-3-7-9}.
It wasn't too difficult to then divide the remaining eight digits into two more sets that sum to 20.
I was quite pleased with this parity break-in. 🙂
👏 brilliant
@@Paolo_De_Leva Cheers. I wasted quite a bit of time trying to apply parity in c2 and c3 first, mind you 😂.
Simon's distribution of 8s and 9s argument is pretty neat too, and probably more straightforward.
@@RichSmith77 Yes, Simon's application of the pidgeonhole principle was brilliant as well:
en.wikipedia.org/wiki/Pigeonhole_principle (see comment by *Larry Moeller, Jr.* below)
Rules: 04:39
Let's Get Cracking: 05:41
Simon's time: 25m44s
Puzzle Solved: 31:25
What about this video's Top Tier Simarkisms?!
The Secret: 7x (03:09, 06:43, 06:50, 07:02, 07:04, 27:33, 29:25)
Three In the Corner: 4x (23:40, 25:54, 30:31, 30:48)
Bobbins: 1x (27:19)
Phistomefel: 1x (02:40)
And how about this video's Simarkisms?!
Pencil Mark/mark: 6x (05:50, 08:10, 18:59, 24:06, 27:46, 28:57)
Ah: 5x (06:47, 13:21, 23:31, 25:30, 27:43)
Sorry: 4x (17:38, 26:02, 26:58, 30:50)
Hang On: 4x (12:48, 16:06, 16:46, 20:27)
Good Grief: 3x (28:39, 29:18, 31:23)
Clever: 3x (01:57, 14:58, 22:20)
Lovely: 3x (18:02, 22:17, 32:17)
By Sudoku: 3x (21:14, 25:35, 29:28)
Naughty: 2x (19:28, 19:34)
Obviously: 2x (11:11, 14:35)
Wow: 2x (31:05, 31:23)
What Does This Mean?: 2x (14:22, 18:12)
Nature: 2x (22:11, 22:14)
Naked Single: 1x (29:29)
Out of Nowhere: 1x (20:40)
Horrible Feeling: 1x (09:19)
Brilliant: 1x (02:21)
Take a Bow: 1x (32:42)
Come on Simon: 1x (22:36)
Masterpiece: 1x (00:44)
Full stop: 1x (01:24)
Snake: 1x (03:09)
Cake!: 1x (02:22)
Most popular number(>9), digit and colour this video:
Twenty (18 mentions)
One (97 mentions)
Yellow (3 mentions)
Antithesis Battles:
High (3) - Low (0)
Even (4) - Odd (0)
Column (23) - Row (6)
FAQ:
Q1: You missed something!
A1: That could very well be the case! Human speech can be hard to understand for computers like me! Point out the ones that I missed and maybe I'll learn!
Q2: Can you do this for another channel?
A2: I've been thinking about that and wrote some code to make that possible. Let me know which channel you think would be a good fit!
Thanks bot!
Good bot boy!
Simon's only weakness is scanning. And tidying pencil marks. And Sudoku. Which makes this ever more impressive. Imagine if he was *good* at Sudoku, he would be a beast.
imagine simon + mark together, I always wish they'd solve one together. Or at least solve the same puzzle and upload both videos
@@bennettgardiner8936 This has happened, not too long ago, I think. If you look at the catalogue of their videos (there is a link under the video) you might be able to find it. I think it was this past summer sometime. (Solving the same puzzle and uploading the videos.) Interestingly, it was not that different a path or even a time. When I watched them, I realized that we seem to think that there would be a huge difference, where in fact there wasn't in that case, anyway. The constructors help the solver find the most beautiful path, generally, and Simon and Mark are willing and eager to follow the trail. So it was interesting in that it was not terrifically ... well, interesting, as I recall.
@@emilywilliams3237 Fair enough! I'll try to find it. I do think certain puzzles would lend themselves to a higher probability of having different solve paths.
Of course these may not be seen as the most elegant as they might had additional clues that aren't necessary for uniqueness.
However I've noticed with particular rule sets, particularly disjoint subsets, that while watching Simon I'm sometimes seeing slightly different ways of getting similar results.
Simon's scanning makes me feel less rubbish! He looks down a column with 8 digits in it and says "and that must be an ... err ... I think it's a five". Unlike Mark who says "there's a naked 3/7 pair here" and I have to pause the video to work out how he even saw it. I'm much more of the former.
Already feared that the video won't be published today
I'm sorry I was a little late. CZcams was being recalcitrant about processing it. We'd appreciate it if people could "Like" the video today to try and make the algorithm realise it's still a wonderful puzzle - just published 12 minutes late!!!
@@CrackingTheCryptic I'll hit that like button with a sledgehammer.
@@CrackingTheCryptic I myself enjoyed the puzzle all the more after waiting a quater hour at it ♥ and naturally gave it a like :)
... and he started with 2 x 256 and in the end there was a 128 in the center. Nice 😁
Simon at 24:08: "I'm not seeing any pencil-mark eliminations..." While he highlights all the possible sudoku digits in the puzzle to consider _except_ he skips the one that actually has an elimination he's missed. And I shake my head in bemused disbelief once again. :)
28:31, I very very much needed my sudoku spreadsheet that includes what all the different digit combinations sum to, can't imagine doing this with all that information in my head. Even after breaking in, it was still fun to figure out the possibilities of the cages and even after that, there was a lot of pencil marking to work through. It was neat that it didn't just fall apart.
After three months I finally dared to do this puzzle. I think I got some gray hairs during my endless efforts. Finally I was able to solve it and am very impressed by this fantastic puzzle.
27:28 for me. I'm becoming an expert at breaking puzzles, apparently. Well, I got there in the end.
Thank you Simon and Cane_Puzzles. What a nice puzzle!
30:25, thoroughly drawn out by the need to refer back to my list of available combinations summing to 20 in four cells. Once I was able to identify the values of r2c4 and r8c4, and from there figure out which combinations of 20 were valid for the remaining cells in c4/5, the rest began to snap into place.
Unless I've missed something... THE 3 SIMON IN BOX 2!!! I can't come up with a lot of the logic as insanely fast as Simon does so whenever I see something easy like that I get very enthusiastic....
My solve couldn’t have been more different. I did not find Simon’s break in, so it took a lot longer. I worked out what the combinations were going to be for the 7 cages (for example, 2 of them needed to be 3458), then figured out which cages held which combos.
52:08 ... I *really* struggled on this one; I spent 20 minutes and (apart from the digits at r1c2 and r9c5) got virtually nowhere, took a break, came back, spent about 10 more minutes, and finally saw what Simon saw with the three cages in c4 and c5.
Tough puzzle (for me, anyway)!
I thought it was harder than what Simon made it look. Your time was very impressive
I'm never able to watch these as they come out and comment early. But I'm on Christmas break! Hello, Simon!
For a 14 year old to set an impregnable fortress (I needed Simon's help where he said 8912 have to be in one of the 20 boxes with both 8 and 9 together) is genius.
This puzzle was harder than Simon made it look.
Loved the Puzzle, although I need a pen and paper next to me to work out number sum combos
That was a weird puzzle. Started off like tetris and ended off like dominoes. (Once you had the right digits, the entire puzzle got simple and fast like dominoes).
18:35 - The whole puzzle can be broken open the rest of the way precisely by answering this question.
(Remember, Sven created a way to see all the possible digits that can go in cages that have specified totals. This is very helpful so that I don't have to keep doing the math.)
Goose honk: 23:33, 25:32
almost everytime: me staring helplessly at puzzle for 25 minutes. Simon in 5 seconds: "where do we start... Oh! I have a digit"
I finally got this, took me 101 minutes. I am not good at cage logic and very arithmetic-heavy puzzles! I used letters to disambiguate boxes 1/4/7 to find roping which gradually led to me replacing all the letters with numbers, which gave me the "peeking" T- and J- tetromino values which allowed me to work through boxes 2/5/8.
Now to see how much easier it is for someone like Simon who actually understands cage logic!
Holy cannoli, my solve path was WAY different from Simon's though a lot of similar logic was involved
Nice, thanks. More taxing than the 15 version as I recall. I used parity rather than Simon's method (as well as the marvellous killer calculator).
Nice puzzle
Oof, this one took me a while. I was so focussed on looking for something arithmetic, that it took me a long time to get my hands dirty on column four and five and piece together the combinations. Turns out being stubborn isn't particularly helpful in sudoku.
wow, i actually have no idea how to solve that.
Killer sudoku grid
Featuring Ottoman,
Just seven cages of
Twenty apiece.
Juvenile setter with
Uberintelligence
Surely his fame will go
On to increase!
👍🏻
This was a nice puzzle, and so was the Pile of 15 from some time ago. Very enjoyable, very interesting, not too difficult, and remarkable that the setter is not only just 14 and can set this sort of thing, but can solve as well as he can. Bears watching, for sure. Simon, your solve is always fun and lovely. Thank you.
Very enjoyable!
Short , sweet, and most directly to the point. 😀 No beating around the bush with fancy , long, look up in the dictionary words. 🫠
@@davidrattner9 some days are like that…🤔
@@longwaytotipperary they most certainly are!! Every comment you write makes my day!! 😁
@@davidrattner9 that warms the cockles of my heart (I’ve heard that expression many times and I think it means I am very appreciative). 😊
27:40 strangely, that 7 in r8c1 was my first digit.
Yet another one finished. Of course I am claiming that by using Simon's terminology of WE worked it out and WE finished to make that claim as i usually do.
A 14 year old! That's a quarter of my age.
24:06
R3C5: „Am I a joke to you?“
31:58 for me. Nice puzzle!
Another one I couldn't get on my own, even after getting a good start with the 7s and the 2/4.
will the phistomefel puzzles be released to non patrons in the new year? i am unable to commit to a patreon subscription but would love to access the puzzles at a later date if possible
25:47 for me. great puzzle
Solved it with help from the video.
Here early today!
Is it possible to tile 80 of the 81 cells with 2 copies of the 5 basic Tetrominos (yes) and have each be a 20 cage (idk)
I know what the unicell would require.
considering how well this puzzle is contructed, it's a missed opportunity to have the cages in the shape of all seven Tetris tetrominos.
This is not possible. please see my earlier comment.
This one took a while, 51:37 for me.
At the 25 minute mark, still waiting for the 3 in box 2.
That was a breakthrough for me - I managed the hard bit about as quickly as Simon did, but then kept making mistakes in the nicely easy sudoku bit and never knew how far to unwind.
A 33 minute video? I'll be able to crack that! Ah.... no. *sigh*
Pew just under ten minutes, 9:58!
Started by working hard on the cages in c4 & c5, got the 3 different combinations, and they were easy to place, after that it fell apart.
There aren't any cages in c6...
How long till he sees the three?
Simon Ella😂
00:54:33
68:30 for me
46:39 for me.
There something wrong with the timer as it shows that I have solved it in 42 seconds :)
If I can't solve a puzzle constructed by a 14 year old then there's no hope for me lmao
What a fine name you have.
I was much smarter at 14