The Miracle Sudoku

[Music] hello welcome to Sunday's edition of cracking the cryptic I hope you're all managing to stay safe during lockdown I were continuing our schedule of doing two videos a day so mark is gonna be back later on tonight with a I think the classic sodoku today he's gonna try a New York Times hard puzzle for you guys so look out for that big thanks for their lovely responses we've had to yesterday's celebration video on 150,000 subscribers for the channel it's a very emotional video for us and yeah it's been absolutely amazing to read all of your comments on it so big thanks also big thanks of course if you support the channel on patreon we've put a bit of bonus content up there today as a anti night puzzle by Mike Haldeman Mike's appeared on the channel I think twice with puzzles in videos and the puzzle we put up is a very nice indeed not easy so do check that out if you're if you're supporting the channel there now what am i doing today you may be wondering looking at this blank Sidoti grid well something a bit different is the answer mark has a puzzle that he wants me to try he says that I have to load the puzzle up during the video so that's exactly what I'm gonna do in a minute I do have the rules what normally happens is that once we've decided which puzzle we're doing I sort of put it into the software and then load it up and I have you know I suppose those few seconds of when I'm putting it into the into the software to think about it but not wants me to have none of that today and literally just going to see the grid for the first time with you guys so I suspect we're going to be looking for something extremely strange but anyway let me read the rules of this sodoku which by the way is by Mitchell Lee now Mitchell is of course a setter for the Galactic puzzle hunt so he is an awfully good puzzle constructor now the rules of this puzzle that we're going to try our normal Sudoku rules apply any two cells separated by a Knights move or a kings move as in chess cannot contain the same digit any two orthogonal II adjacent cells cannot contain consecutive digits so there is a that is quite a big restriction on this grid so let's just talk a bit about what that means if we try put a 1 in the middle the Knights move constraint says that if this was a chess Knight it could jump to all of these cells and therefore none of these yellow cells can contain a 1 now the kings move constraint is going to work by as imagine that was a 1 this time now if this was a chess King obviously you know the 1 removes all of these cells from being ones just because of normal sodoku but if this was a chess King it could also move to this cell and this cell so neither of these yellow cells could be a 1 in this iteration and finally what have we got we've got any two orthogonal ei jacent cells cannot contain consecutive digits right so that means that these four cells could not contain a tube in his the Doku so yes there's an awful lot of restrictions going on right now with that let me see if I can how do I do this I'm gonna have to let me just see if I can in there let's see what we get right they've got to be joking there is no way that this well it might have a unique solution but it's not gonna be findable by a human being I suspect this is going to be a short video because he is trolling me and although I can put a 1 in this box in the central box so right I'm gonna give this five minutes and then we will probably turn the video off and you'll never see this and yeah he's gonna get an angry phone call otherwise this is going to be a work of sublime genius and it will appear on the channel so let us if you want to have a go should say that you want to have a go click on the link under the video to play the puzzle and with that let's get cracking now why do I think I can put a 1 in this box well it's because of all these massive constraints on the grid those can't be once by normal a sodoku rules those two squares are a king's move from this cell so they can't be one the use of a knight's move from those squares so they can't be one and that square is adjacent to a 2 which is consecutive so that can't be a one so the one does in fact go there and there by because that we can't put a 1 ever next to a 2 so there is a little bit we can do here now let's check this to does it rebound in here I believe it does doesn't it because look these ones all of a sudden had a potency because they can't have a 2 next to them so all of those quests can't be 2 and this 2 sees that one by knight's move so this is a 2 and that's a 2 because it can't be next to a 1 right but this is probably where you can't go any further because I mean there's just no communication in the top or bottom of the grid here although having said that having a sin that where do we put the one in that row okay this we may actually have to take this a bit more seriously because this this one rules out that square by Knights move that by sodoku that square by Knights move this one rules out that by Kings move that by sodoku and that by Kings move and that by Knights move and this one rules out that one as well so this square is a 1 so there's a 1 down there this can't be a 1 because of the Knights move constraint and now now in this row 2 is restricted as well because this 2 sees that 1 by knight's move that like king that by normal King Knight normal from this 2 so the 2 is in one of those two positions so the 2 is in one of these three cells in box 2 ones have got to be the ones have got to be in one of those 3 cells can we do any better than that we can't quite use the consecutive constraint because it it you know if I make this a 2 the one could escape to there look so we can't quite use that so we're gonna have to look we're gonna have to look lower down the grid and unless I've missed a restriction there I can't see what to do at the top I mean I suppose that one rules out that square that square that she the two is quite restricted even in this square so the two can not go here here here or here so two must be in one of those three cells still not good enough right let's have a look down here so the you're kidding look the two the two in row seven this one rules out that square that by Knights move this square could be a two this one can't this one can't because of this one Knights move King's moved to this one King's moved to this one Knights move I don't believe it that is a - that one's not a - therefore so now - ah look choose this - seize that square by Knights move so the two must be in one of those two cells and now where does a to go in one of those three cells this one rules out both of those that you must go here that gives us a two at the top that that one can't be - now don't believe it this is so now we know the two is in one of those cells that can't be a 2 this is a 2 we now can't put the 1 here because it will be next to a 2 sorry can't put the 1 there the one shifts here and must be in one of these 3 squares and it can't be next to a 2 so it's actually one of those 2 squares you are kidding now yeah look this box where does the one go this one rules out those squares the two and the one rule out this square this two rules out that square this one is for all two helper the King condition this one can't be a one because if it's a one neither of those squares can be a one this one by sodoku that one by the Knights move so I think we just left in this box we just left with those two cells to be the one and that means that's not a one oh my goodness what is going on with this puzzle don't believe it the one is restricted to those two squares in this top box because this cell sees that one by the Knights move sees that one well either by Kings move from the one or orthogonal II adjacent to the two this can't be a one this is the one you are kidding so now we get left with this arrangement of ones and twos at the top now that's this arrangement is quite interesting as well it's sort of symmetrical but if we try and put the one in the too far apart in either position in the other row it will move them together and that's not allowed so actually we know that the one in the two must be exactly one cell apart wherever they appear ah my goodness so right but this is probably now going to be impossible because now we've got we've got ones and we placed some twos but the threes which must be where we have to go now because we know nothing at all about four five six seven eight or nine we know that threes are restricted by tubes that is all we know so three for example in that box have to go in one of those positions but in this box they can go just about anywhere they can't they can go hit the can't go in one of those two squares because then they'll be a locally adjacent to a two so they can go in five positions in this box they can go in and that this is just not gonna solve there's too many places they suppose they can't go in they can't do net ever next to a two so yeah I mean look at this this is just and in this box well this is this is about this box is about the best box because this 2 and this 2 rule out that square and that Square and this one rules out those 3 squares so - sorry 3 is restricted there and I'm going to color all of those in right so the the sort of the theory is that apparently we can resolve this pattern into threes that are solvable no way well that one can't be a three let's put that I can see that because the threes of one of those two places that one can't be a three because if we try a three there it rules out those two and that one by the Knights move constraint so actually we can do another digit there that one can't be R I'll be a three see that one can't be a three either because if that's a three look it has it rules out that one and that one and then the Knights and the Kings move constrain rule out those two as well so this one isn't a three either it's actually amazing how much of a restriction this or this combination of rules turns out to be but it's it's still very hard to believe that it's going to be enough to resolve anything here that squares quite nice that can't be a three because if that's a three it rules out that one that one by Kings move and those two by Knights moves so we can get rid of one more delete and color that one also look now that one is that's amazing so this one can't be a three because it rules out this sort of tetris shape from the middle box rules out that one that one those two by Knights move and that one by Kings move so this is not possible now now this one is not possible because it sees that one that one and that one by Knights move you have got to be joking now we are getting somewhere aren't we because now we know the three is in column one in this box so that is not a three now this isn't a three because it would see both of those by Knights move I don't believe it this isn't a three now it sees every one of those three squares so now this isn't a three by the same logic it sees all those three squares and now now we've got a domino here so this this isn't a three this can't be a three um and wherever we put the three in fact this that's very interesting whenever wherever we put a 3 here either they're all there those two can't be a three because effectively you can ring a domino it's a bit like a Star battle or star it can't touch anything I'm not sure if I'm making myself clear there but let's just imagine this was a three if this is a three you can see it rules out all of those squares immediately by the kings move constraint but it also sees these two by knight's move and that one by sodoku so it rings the entire Domino so actually wherever the three is here neither of those can be a three and I this is just staggering this is absolutely staggering because now look we've got we've locked the three into a column a and column nine in two different blocks so we now know that in column seven the three must be in this Domino here and we know that therefore those are not in a now look row eight nine we've got the trees locked into the same two rows in two different boxes so this neither of those can be a three the three we we've got a three in them we're going to get another three and another and another I don't believe this the threes are placeable from that absolute gibberish we had in the grid what this is this is magic this we are watching magic unfold here oh now look dis 3 this 3 is next it can't be next to a 2 the 2 must move here therefore that's the one this is the one and this is the 2 and we disambiguated all of this as well oh my goodness so now we move on to falls presumably we've done all the ones all the twos all the threes you you could not believe it now it's possible the fours are going to be easier you know because there's less space in the grid now fours are already quite restricted and packed in this box the 4 must be in one of those two cells this is going to solve isn't it this is going to solve I am pretty dumbfounded I have to say that is if this if this solves I'm not sure I've got the adjectives to describe what is going on here this is like this is like the universe is singing to us here this is just absolutely unbelievable fools right so the force here rule out that one we've got a domino here we know what we do with Domino's they cannot have fours anywhere near them that place is a four places are four places of four places of for this those two are both ruled out that one by the Kings move place that four place this four for here it's just absolutely unbelievable the force the force were easy let's get rid of the coloring and move on so fives now so already yeah the fives are restricted they are very restricted it can't be next to a for that whoa whoa look at this we're gonna be able to place a five in this cell immediately and here that's the only place of five and go in the block three knives we almost don't need coloring here I'm gonna keep going with it that one is much worse there look like and go in a lot of places and there okay so where do these flies resolve all this one obviously it must be a five that must be a five therefore that resource everything there this five sees those two that one this one that one that one and that one and we're done with vibes as well I have to say this this is something extremely special now can we keep this going so sixes must be in one of those two sixes and our six in this box must be here because the five sees both of those and that five sees that square so now the six must be in one of those two cells both look possible at the moment this five sees those two so we can place a six up that one that five sees that square the six placeable in that in the center this hick sees that by knight's move so that six must be true that's the only place the six can go in the bottom sell six must go here that resolves the six at the top six must be in this square and what do we say are those that must be a six that must be a six and therefore this must be a six so now presumably yes seven look we can just write a seven in because the six and this this six and this six rule rule out both of those squares so the seven Moscow here a plate that this must be a seven we mustn't put a seven next to six that must be a seven this seven by knight's move sees that one sees that one that's a seven that's the seven that's a seven this is a seven must have noise avoid the Kings move constraint seven down here look must be in this square which means the Ducks are seven and I think we've done the seventh and the eighth eights and nines are just going to resolve all we've got to find as a seven that's orthogonal II connected to something or that where there's a gap next to a seven this seven look this square here now cannot be the eight so that's going to completely trip the whole puzzle isn't it we are watching something extremely special here this Mitchell II has come up with a work of sublime genius that's got to be the eight that's got to be the nine yes Wow oh my goodness me now let's just take a stare at this because that there must be something going on in this grid we've got the central cell is a nine so I'm just wondering if we've got symmetry here let's click all the nines and highlight them and then have a look so have we got yes we have rotational symmetry so though eighths and the ones are always reflecting onto each other look at that so wherever 1/8 appears if you rotate the grid through 180 degrees you always find a one look at that absolutely mesmerizing oops miss click there but you can see this 1/8 here reflect up there onto that 1/8 at the top the 7 is reflecting onto a 2 always the 3 is reflecting onto a 6 the fours and fives are reflecting onto each other as well oh my goodness me well that that grid is something that you should just take a photo of and preserve to posterity that is an unforgettable puzzle unforgettable I should thank you Mitchell unbelievable thank you Mark as well you yeah I very nearly clicked stop on the video actually and rang you to berate you but no that was that was something special I hope you enjoyed it let us know in the comments I don't know what to say absolutely amazing you

Channel: Cracking The Cryptic

Views: 2,683,550

Rating: 4.9648604 out of 5

Keywords:

Id: yKf9aUIxdb4

Length: 25min 48sec (1548 seconds)

Published: Sun May 10 2020

Reddit Comments

[u/SelectAll_Delete]

"This isn't possible, this won't be solvable."

Cut to:

"This is staggering. This is magic. This is like the universe is singing to us here."

[u/ms4]

Why did I watch this whole thing. I have so much work to do.

[u/ExponentialHS]

As someone who barely knows the rules of Sudoku, this was so satisfying to watch. He does an outstanding job explaining the rules and his thought process. I love how the odd rules seem like a frustration but are actually the key to solving.

[u/Justavian]

Stumbling across this channel a month ago, i was suddenly inspired to try some sudoku. I bought their Steam game "Classic Sudoku". It's very difficult for beginners, aside from a few gimmee puzzles. Even after learning a bunch of the more advanced techniques, i still find myself "cheating" by choosing a cell that's limited and randomly giving it a value. Then i play it out and see if it breaks. It works, but it doesn't feel quite as fulfilling to solve it that way...

[u/Anaksanamune]

No matter the subject, there is always something amazing about seeing the reaction of someone who is a master and has "seen it all" on them seeing something completely new.

Must have been like a ray of light for him to find something so original, challenging and yet satisfying.

[u/Sir_Martinelli]

The ending made me feel like Mathew McConaughey at the end of Interstellar.

[u/jocelynwatson]

The thing I noticed more than the symmetry is they number line repeating row by row “483 726 159” then the next row down “726 159 483” then “159 483 726”. The rows continually repeat the same numbers in a row.

[u/jmosgrove]

I have never played 1 round of Sudoku in my life and happily watched the whole video. I have now happily played enough Sudoku for the rest of my life.

[u/Denarim]

Cracking the Cryptic getting more attention!? Yes please! This channel is an absolute masterpiece of wholesome challenges and puzzles.

I love Mark and Simon so much. I hope this gets traction and opens them up to a whole new audience!