Can You Name A Better Puzzle?

[Music] hello and welcome to wednesday's edition of cracking the cryptic in what i suspect might be a very very long video for today i'm going to be attempting this puzzle on screen which is called yin yang by jasper jessica josephson um and jasper's puzzles are always fantastic and i think this might be the puzzle that we've had recommended to us the most of any puzzle in our history this has been absolutely lauded to the rafters it is apparently absolutely extraordinary um but you know great setters and soldiers like knt said it took them three hours to solve so i'm expecting this to be probably the longest video that we've ever made if indeed i can solve it i have read the rules and they strike me as utterly ridiculous [Music] but anyway that's what i'm going to try and do today uh i knew this would be a long video if i managed to solve the puzzle so i have allowed myself extra time in order to hopefully record a successful solve we shall see um before i do read you those rules though i've got a couple of things to mention i have actually recorded a bonus video um of me solving some of the daily pencil puzzles from the discord server these are wonderful little vignettes sort of ten minute puzzles beautiful beautiful things um and the guys over there were kind enough to send me a list of their favorite five puzzles from the last few months and so i've recorded a video where i solved those and probably if i get a chance i'll release that on the channel tomorrow morning so look out for that if you're interested in pencil puzzles and if you're watching this video why wouldn't you be interested in pencil puzzles they are fantastic things um other than that i need to say congratulations to some more of you who've managed to solve joseph neymar's sudoku hunt now that's available at the moment over on patreon it has been getting the most incredible plaudits and very well done to the following who have solved all 13 of those equal sun lines puzzles um grey kanarek um eric snell charlie skeira stephen williams joseph costal nicholas owell todd warnken and marie de haan esmeralda will be proud anne marie jake ferentz konderviltz justin kidman harrison beer uh john andrew mcculloch and tran chi-hui uh i hope i'm saying that last one correctly i did my best i promise um so yeah all fantastic all correct very well done indeed now let us start this puzzle let me read you these rules they are mad um divide the grid into regions so you can see normally in sudoku we get three by three regions in this puzzle no such luck and we've got to divide the grid into regions each consisting of nine orthogonally connected cells each row column and region must contain the digits one to nine once each shades themselves so these conditions are all fulfilled all shaded cells are connected all unshaded cells are connected no two by two area is fully shaded or fully unshaded and each region is either fully shaded or fully unshaded the digit in a cell with one or more arrows is equal to the total number of shaded cells that appear in the indicated directions combined not including the arrow cell itself not all possible arrows stroke arrow combinations are given oh my goodness me so let's let's take a look at this cell that seems to be the only cell that's got four arrows in it so what if we let let's put a no let's put a 5 in there just for the sake of exposition what that that five would be saying i think is that in these cells these cells this cell and those cells combine so in all of those purple cells there would be a sum total of five shaded cells so therefore all the others i suppose are unshaded that's the corollary of that um [Music] and let's in fact now let's abandon our purplification of the grid and think about these yin yang rules because this is it strikes me yin yang is a very popular logic puzzle um and this rule set appears to me to be very very faithful to the to the classic yin yang puzzle type so what we're being told is we've got to divide the grid into basically you know two areas one of which i'm just gonna draw in some stuff here i'm probably gonna fail actually whoops um let's imagine that i need to make sure there are no two by twos in the area that's left behind yeah so let's imagine that they were the shaded cells and let's imagine that these were the unshaded cells and let's revisit the yin yang rules to see if we have we have met these so what we've got to do is have all shaded cells connected well all the purple cells are connected um all the unshaded cells all the green cells you can see they are also orthogonally connected no two by two area is fully shaded or fully unshaded that i think is true i don't think we've got any two by twos filled with one color um and then if this was the pattern in this grid we would then be being told that each region so each of our nine cell regions in the puzzle has to be constructed so actually that's quite interesting isn't it if this was correct the top row would have to be a region and then the next region would delve down like that the next region would sort of twist around the corner uh is that nine cells yes then the next region would do this and one two three four five oh i thought i was going to be correct then i was going to be amazed but no this this is not the correct pattern perhaps unsurprisingly because um that this could only be an eight cell region and it would need to be a nine-cell region so this is not the correct pattern no surprises there but i think that's how the rules work now do have a go um the way to play is to click the link under the video i would suggest if you do have a go that you allow yourself some considerable time to solve this everybody who solved it says it takes a long time but now i get to play let's get cracking and see how we can solve this puzzle so my temptation when we start here is to find arrows close to the edge like this one because presumably that can only see a maximum of three shade if all three of those were shaded this would be a three so that must be a one two or a three [Music] not seeing anything else but well that one's quite near the edge that's got to be one two three or four i suppose i'm not seeing much else here this one well this one's got two arrows in it which is a little bit annoying but both of the directions it's pointing in are relatively close to the edge so that cannot be higher than four but here's something here is something how could that be four well if it's four all of these cells would be shaded we have to discover we have to decide what we're gonna use for shading let's use gray um so if this was a four and these were all shaded then how could there be an unshaded cell in this two by two in the corner and the answer is there can't be because that unshaded cell could never connect to any other unshaded cells in the puzzle and it's not possible for the whole of this top right region to be gray because then we'd have lots of two by twos in grey so but but the problem then is if we say there's no no unshaded cells down here these all have to be shaded and then they're all gray and now i've got a two by two of grey so this doesn't work so this is not four um this is i think a maximum of three three no three would not give us a problem because any greens in here we can then escape with without leaving a two by two behind so this cell is perhaps the most interesting we've found so far wow there's not much else that's really close to the edge i don't think that one is obviously close to two edges but then it's got an arrow pointing this way rather annoyingly that one has got to be one two three four or five it only sees five cells beneath it um right it might be that we have to think about things like these two cells because they are looking at an awful lot of the same cells what do i mean by that well look at these two cells i'll just make these cells blue for a moment the arrows in them are pointing to sets of cells that include these purple cells these purple cells are common to both of these arrows these arrows are going to count the number of gray cells in the purple in both directions so if there were three grey cells in this purple strip that would contribute three to this one's total and three to this one's total so what that's telling us is that this domino here and this domino here must have a different number of shaded cells in them because imagine there was one shaded cell up there in this domino and one shaded cell in that domino at the bottom well then these two arrows have the same total we don't know what that total is but it would be the same so i think that's quite interesting i don't see it really how to use it immediately but i'm i think we're going to have to keep track of places where we need an inequality in shaded cells but i think i'm going to have to start labeling cells that can be one of five like i did with this one that can also be one to five look i wouldn't have thought the idea of the puzzle is to label every single cell that would seem well it would seem unlikely to be helpful there must be a cell in here somewhere that is under so maybe it's this one that's under surprising pressure right so this one is pointing in two directions that in theory could contain lots of shaded cells but this digit obviously can't be greater than nine so that means that there must be some unshadedness well that's not very surprising oh ah okay i've just had a thought about the nature of yin yang puzzles let's just yeah okay let me just talk about that for a second or two um let's think about the perimeter of a puzzle that has yin yang characteristics and ask how many contiguous sequences there can be in the perimeter and by a contiguous sequence i mean how many times can we change color so if we're what are we saying we're going to use gray for shaded so if we go grey for shaded and then green for unshaded could we ever do something like that and the answer is no because the moment that you have more than two colors or more yeah more than two stretches of color in the perimeter you have a problem which is how do you connect these grays together or how do we connect the greens together and the answer is it doesn't matter but you know the grays have to connect together so however you connect them together you're isolating the greens from each other and that means that however we however we plot the perimeter of this grid is going to be a set of shaded cells and a set of unshaded cells you know there's only going to be one of each um so i was just thinking then that this clue well it can't be a zero it can't be a zero can it so there must be some shaded cells in well i suppose it does they don't actually have to be shaded cells in both directions but there must be some there it must be a shaded cell in that sequence of digits and that sequence of cells and there must also be unshaded cells in this sequence of cells so but we've got to make sure yeah so imagine this cell was shaded and this cell was unshaded then we'd sort of know that any unshadedness in the perimeter must extend from here and any and shadedness must extend this way and we couldn't have interruptions anywhere else um okay i'm not sure what that means but i think that there i think there's something about this cell this cell feels interesting okay it can't be this one can it i mean this one is tempting because it's the only four cell arrow but i think actually this cell is horrible because it basically is looking in so many directions ah those two are looking at each other and they have an awful lot of commonality right let's think about that just for a second or two so these two arrows look at each other and they both count all of those purples so there must be an inequality in terms of these two cells however many cells of these two are shaded must be different to the total to so if that was shaded if this one was shaded either both of these would be shaded or they'd both be unshaded if this is unshaded then at least one of these must be shaded okay no sorry i thought that might be interesting but no this is very tricky i don't actually see how to start this i think it's interesting for sure i don't really like any of these cells that have two arrows in apart from that one that felt like that might be the break-in i might come back and think about that in a moment that's another five cell that's only got a count of five that's only got a count of five as well ah ah that one is looking in the same direction as this one ah right right this is the best we've got so far because now whatever this is any cells in this strip any shaded cells in this strip of of purples give us the count of this cell but obviously this uh whatever's in there is also counting those and yet this must be a different digit to this which means at least one of these two cells is shaded so so now do we get to use this one then if we know that at least one of these two is shaded so this domino here has at least one shaded cell in it in order to ensure this has a different count to this yeah so can't i say something like look at that cell that's saying that there is a non-zero count of shaded cells in that string of digits so imagine that there was a shaded cell here now i have to connect whichever one of these is shaded to this along the perimeter so i either have to go that way or i have to go that way right so hmm is it true to say then i feel like it is true to say that either this column is totally shaded or this column is totally shaded because let me just think about this there's definitely a shaded cell in one of these two there's definite even if this shaded cell even if this was a one and it was the only that cell that was shaded how do i connect this cell to this cell given this thing about the perimeter only having two strings of digits in it well either this comes up here and connects there and then it could go round again but it must you know either it does that or it comes around the other way and gets here in which case it takes that whole string of digits so one of the right either column one or column nine is completely shaded which one of those is broken um that one actually is saying there's definitely a shaded cell in this column so if you have a totally shaded column oh if that was totally shaded what would this number be oh what would that number be right this might be where it breaks then uh let me just think about this if this was a continuously shaded segment this digit is therefore an eight oh but that could be well that would have to be nine because it can't be eight but it clearly does count all of those eight cells so that actually doesn't look like it's broken rather annoyingly um [Music] so this then could be well depends depends how this one moves doesn't it but all right let's have a look at this instead if that's all gray then this cell would be a that would be a seven sorry i know i'm just being silent now but that's because i can't really understand how this is going to i feel like this is quite important but i don't really understand how to make it break in one of the directions it's really constrained this is probably going to be correct is my feeling because it it gives us two digits one of these would be great gray some something up here has to be gray as well from this one so something up here is gray ah okay ah right it's broken wow okay this is very complicated indeed but it does this is broken with gray on the left right i think the reason i reached that conclusion is that because if this is if this is all in the only way it works is with an eight here and a nine here now the corollary of that is that there must be a whole sequence of greens in the bottom row don't know where they are but there must be some greens because this is saying there's only one gray cell in this direction so there are some greens down here let's just put some greens in now this is telling us that there are some grays in this sequence of digits now let's put the absolute minimum number of grays in let's just put a gray in the corner there there could be a gray here as well but but the point is that if and there is if there is a gray in this sequence how do you connect it to this gray we know it must connect because we know there's only one contiguous sequence of grey on the perimeter and we can't come through the bottom of the grid because of the greens that we know must exist in the bottom so we have to come all the way across the top and that i think is broken for this reason if this is a continuous sequence of gray what number is going in there and what number is going in there and the answer i think is far whoops 5 in both of them that's counting those this is counting these so you can't have a stream string of digits along the top of the grid and that means well that i think that means this is wrong i don't see how you do it with a grade strip down the left so my intuition which was to say this is probably right i think is inaccurate i don't think it can be right let's just let me just really really check that i think that's true i think it felt it felt convincing when i explained it to myself just now um this would the only way this is going to be right is with an eight here this therefore must be nine because it can't be eight there must therefore be greens here this is telling us there must be grays here this greys can't connect along the bottom so they must connect along the top which means the whole of the top row must be gray and it can't be that is i think fair i think it's fair so we can let's get rid of the gray let's get rid of the green let's grayify this column entirely now because we need to connect whatever this is pointing at to this and we now know we can't do that down the left hand side of the grid so we have now a whole sit we have a digit that cell there has to be a seven now because we know one of these is gray we've got to get this to touch one of these don't we that actually let's get rid of the eight and the nine they're they're obviously not right i say obviously not right i don't think they can be right because i don't think we can put that strip of gray in although now i'm wondering whether no well i'm wondering i'm actually wondering whether we could do something like this and have a green gap in the middle that would correct these two so maybe we can do both i'm not sure about that um [Music] uh anyway let me right in order to connect this gray to whichever one of these or both of these which is grey all of those have to clearly be gray don't they now hang on hang on hang on right here's something interesting i think remember we worked out that we can't have gray and all of the top row well that means there is some unshadedness in these four cells here now there's only one sequence of unshadedness in the perimeter so whichever one of these is green is going to have to continue on its way around the left-hand side for as long as green goes down the left-hand side which could be no it can't be all the way down i don't think there's much green in the perimeter of this puzzle i just don't think there can be because whatever's green up here this is telling us that there's a non-zero number of grays in this column so hmm i'm getting very suspicious i've made a mistake now because i want to say that this is implying the whole of the bottom row is gray because how could it not be it's not true to say that all of those cells are gray that must be true if all of these were gray these two digits would have the same total so there is a green in here or many greens but it's also true to say that there is a gray somewhere in this string of digits so let's put that gray as far away from this cell as we can to allow the green string to be as long as it possibly could be that would put the gray there if the gray is here then to connect this gray to here we know we've got to be going around this way because we can't come across the top because we'd have the problem with these two cells so the furthest down the column we can put the gray is here but we still have to connect along the bottom to connect this one to its friends so i think the whole of the bottom row is grey now that means this cell is either eight or nine because it's either counting exactly these cells which there are eight of or it's counting another cell that appears in this column so this has to be really small now because if this was a nine there's one more grey cell in this string of digits and this cell which which means that this can only possibly be seeing two cells so this is a one or a two and most of this column is green wow oh this this digit i know it that's pointing at six that's a six at least i'm getting at least i'm getting started that's that makes me hopeful hang on what is that given that we know one of these is gray and we had to connect it to whatever was in this column therefore we said all these were gray that's got to be a 5. so this can't be a 5 now so i thought i've got three digits now that's not a five by sudoku what's this counting this is counting this way oh oh right we can't have two by twos that are full of um the same color in this puzzle so that and that have both got to be unshaded and that's two unshaded cells at last now what can that be then that cannot be four because if that's four all of these would be shaded and we'd have two by twos of shading down here so it's definitely not before i'm not sure it can be three if it's three i don't know maybe it can be three if it can be three if those two are shaded and this one was unshaded right okay that's that's fine though at least we've got somewhere now so hmm i know i know one of those is shaded don't i because i need this to have a different total to this oh so this right so this is a maximum of seven now that's six or seven because it depends what what which of these is shaded it could be both of them in which case it reaches a count of seven or it could be one of them we know it's not zero of them because then this would be a five so this is quite a high number and this one is counting this cell and whatever's shaded here so it's at least a two now how do we do this now so where i've got almost wondering whether this is a sort of a troll puzzle and there's going to be heart you know there's going to be sort of one green in the perimeter and the whole thing is going to be no it can't actually that can't be true because this can only i know most of this column is green isn't it because this can only this is seeing eight it could be a nine in which case it's still only seeing one shaded cell one more shaded cell in this column so either all of this column is unshaded or all but one of it is unshaded so how could this ever be shaded it can't be can it because if that's shaded i now know all of these are unshaded but i also know because this cannot be a five that something here is unshaded and there would be two lots of unshadedness in the perimeter that would once you connected them would isolate this cell so this cell is unshaded right and that means that where the shade if there is a second shaded cell uh what what i mean by that is if this is a nine and that means one of these cells is shaded we now know in order to make sure that the greens are contiguous in this column that we can't put that shaded cell there and have the greens like that because then once we connect this to its friend these greens will be isolated from this screen and that won't work so the only place if there is a shaded cell in this column it's here which means all of those are green now what on earth do we do next oh bobbins i was hoping i could use this one but i can't that being green hasn't corrected the count that could still be three and those could all be shaded and the greens could poke in there like that um oh no no that can still be five how there's got to be some shadedness in these two cells as well because whatever this count is it must be different from this count which requires there to be a shaded cell at least one shaded cell in that domino but it's a little bit less powerful that observation because it's not on the perimeter all right okay gosh i had 35 how about 35 minutes it feels like i've had about 10 minutes um wow i'm not i'm really not sure where i meant to look now oh now it's about to get excited about this cell but of course it's got a down arrow as well which could have any number of shaded cells in it that can't be four anymore because this is green so it can only reach a count of three for a maximum ah got something got something right those two arrows they're counting that string of digits i think we looked at this earlier so that so the count in this cell and the count in this cell we can effectively ignore these cells because these contribute the same number to both of these but we need these to have different counts overall now this one is definitely seeing a shaded cell there so if this was shaded then the count in this and the count in this i'm going to claim would have to be the same number because they're both counting all of purple plus one shaded cell this would count all of purple plus this shade itself so that is unshaded and if that is unshaded these two are both shaded because we can't have two by twos of unshaded because of yin yang rules good grief oh and that doesn't help me there of course it doesn't oh but that means this cell now is not able to be five anymore so this is now a maximum of four which might be interesting so this digit oh hang on it's a maximum of four but it's a minimum of three it's already seeing three so this is three or four and this has to be either one or two more than this so this is either four five six but it can't be seven now because it can only see a maximum of two more shaded cells and whatever this is so that's four five or six here's an interesting point i'm going to claim this is a shaded cell now is that justified well let's look at this domino we know that there's a shaded cell at least one shaded cell in this domino if we were to decide that this was green therefore we know this would have to be shaded in order to make sure this was not equal to five but now i've got two contiguous i've got two stretches of green on the perimeter and once i connect this screen to this screen this will be isolated from the rest of the gray so that's not right so that is gray that's almost useless but it's still another shaded cell um okay what we might have to do then is to think about cells like this because what i'm thinking here is how many of these cells can possibly be gray and it's not as many as you might think at first blush because we can't we can't put more than four in there because if we did the fifth one would create a two by two of gray so that cell is one two three or four i think um that cell has to have a different count to this cell doesn't it ah so this this is interesting yeah let's compare this one and this one for a moment because they obviously both see all of that stretch of digits and that means for these two to have a different count this one must see some shaded cells in these three cells now it can't see three shaded cells in this string of digits because that would create two by twos of gray but it could see two so this is a maximum of two different from this which means this but it must it must always be at least one different from this so this this cannot be a one then no because then that would be a one as well so this must be at least two although i fear that that's not going to work so i think that's doing something weird with this digit but let me just think about this so two three four or maybe five five would require this to see though to make those two both shaded one two three no that actually that doesn't work because where do i put the others after that i could make these two shaded but now this three needs to be correct which means i have to shade those two as well and i'd have a two by two so that's not five so this is two three or four ah right okay right let's forget like let's unbluefy these and think about those cells now those cells are common between these two counts which means which means how is it the case that this one has a different count to this one overall well the reason is that this one sees this shaded cell which means if this was shaded this one would also see an extra shaded cell because it would see the purples plus this but this would see the purples plus that and they would have the same count that's not possible so that is unshaded and if that's unshaded then this cell is now an eight because it's only seeing those cells good grief this is ridic i mean think about constructing this for a moment because we haven't even started to think about how to grow regions out of this nonsense it's completely ridiculous that this i mean this is like a very complicated logic problem to just plot the the way that the yin yang works this this is where you realize that some of the constructors who are now featuring on cracking the cryptic they are just ludicrously clever people so ah so the other the corollary of that being eight is that that little one is a one which doesn't do anything but but now there is a relationship isn't there between these two cells we know that the count of this one is exactly one greater than the count of this one so that can't be four anymore because we need these to be in a relationship of one with each other because this cell gets counted in this count and doesn't get counted in this count so if this is one this is two and then that would need to be three and that can't work ah ooh yeah that does not feel right at all so if that's one that's two then that has to be three by sudoku but then those two have to be shaded and that one's definitely wrong in that case so that's nonsense which means this is not one which i think means this is not two because we know that this is one greater than this okay so we get i see so we're getting some latitude now um so if that if that's two that's let's try it with two so that's two that's three and that's one does that work so now no um oh maybe actually maybe it does because then those two can be shaded that corrects the count for this it corrects the count for this and this is just naturally correct it's seeing that one ah that does work wow okay so one possibility is that we go two three one now the other possibility then is we go three four and what would that then be i feel like i should well it's obviously one or two i do realize that um if this was one this couldn't get a count of four could it because it can only see because this one is saying it's seeing that one only so these these would only have one shaded cell in and i can only put two shaded cells in here so this would be incorrect so this so right so this then has to be two three four like this so either either this goes two three one or it goes two three four so there's always a two and a three in these cells which is a little bit interesting to me at least yeah i'm available for dinner parties um so if this is two this sees one here oh but it's still the case that both of those have to be shaded so whatever yeah there's always a difference of two between these two that's the point and that's interesting because that means the only way that this can be too greater than this is if both of those are shaded wow which means that's unshaded that's unshaded by the power of two by twoness and now this is known this is now a two i want to say it sees that one and that one so that's a two that might doesn't actually tell me whether that one's oh i tell you what that's not gray i'm suddenly thinking i didn't know what this is but i can tell you it's not gray because if it's gray that green is isolated so that's got to be green ah now here's an interesting thing about yin yang puzzles look at that little collection of digits now what would happen if we had a checkerboard so what would happen if we made this gray well then you get a problem uh and perhaps the best way to show this might be to just take this problem let's put it in let's put the checkerboard over here so if we had double gray and double green like this in a checkerboard and a yin yang how do you connect these greens together and the answer is it does not matter however whatever journey you take to connect these greens together you can see you're going to isolate this gray from this gray you can't then connect the grays together without crossing the greens so you can never have a checkerboard and that means this cell cannot be grey that's green and yeah that doesn't seem to do very much does it um well although this digit is now getting a little bit more constrained one two three four five that's a maximum of five it doesn't seem to be able to be five so that's got to be a two three or a four so it can't be a one um so that's two three or four that's two three or four six or seven this is now done that's done that's a four it's just seeing four that's his count we can't we can't improve upon it so that's a five or six that's a six or a seven um okay what do we do now now we will use the power of i don't know i don't know where to look we shall oh that can't be two it sees a two here so that's three or four now at the moment the cat has a count of one so if this was a four three of these would have to be gray this is five or six hang on how can how can that be six now can't be six can it i've got four in the column so if this is six i need to see two oh yes of course it can there's no i was i was getting myself confused because i've been thinking about down here where we have to be concerned about two by twos but here there's no restriction on both of these being gray so that can be a six bobbins right okay um ah i know what we're gonna do what about that digit because those two are looking at each other and they therefore have commonality so that must mean let me just think about that so these are common to the count of this and the count of this so that means this domino must be different from this domino in terms of the number of shaded cells now this is interesting because this definitely has a count of two shaded cells in it so that means these cannot both be shaded because if they were both shaded the count of this and the count of this would be the same but here is something that you can't make both of those unshaded either because that would create a two by two in green so that means one of these is shaded and one of these is unshaded which means that the count of this cell is one less than the count of this cell because this one sees two shaded are beyond the purple this sees one shaded beyond the purple so this it sees one less than this so what is this then it sees two at the moment it sees three up here but it can't be a three because then that would require this to be a four so it's got and it can't be a four because that's going to break that so it must be it must be a five wasn't it because if it's a 6 that needs to be a 7. so i think this has to be 5 and this has to be 6 and therefore that's 7. wow this is just stunning isn't it it's stunning now but that must mean that means both of these are grey because that's what we were just thinking about i was worried about making both of these great i was thinking about i was in two by two world which i'm not so now this is five one two three four one of those is five this is six one two three four five six this is seven which is oh that's huge right because i'm only seeing six so that's got to be grey so both of these turned out to be gray in the end so now what's that one two three possibly four so it's not two anymore so now i've got a three four pair here so the rest of this row has got to be two six eight and nine and some of these have got arrows in them that's got a six in its column uh ah well i'll tell you something that can't be two because it already sees three using its arrows so that's an eight or a nine which means most of this column is is gray um it sees two and even if this isn't eight that means it needs to see six here it sees one here so at least five of these uh at least five of these seven cells are gray what about that one that one is just a single arrow looking downwards so even if everything was shaded that would only reach a count of seven so it's not eight or nine so that's just two or six okay if that's four don't i run into a problem with this now and two by twoing if that's four three of these four have to be have to be oh you could do that three of this these four have to be shaded but you have to avoid making two by two so you'd have to have those three as shaded which makes that whoa right that doesn't work right that's not for and that is for a horribly difficult reason but let me explain look at this column now how are we going to make it work well because we've got this stripe we could put the only way we can complete this four is with a string like this but now this is almost a two by two so we've got to make that green but then we know one of these we know that this was one of each so this has to be gray and now that means this count is a four so we get two fours in this row and that won't work so this is a three and this is a four and if this is a four now we know this is gray in order to make this count work so that gets gray that therefore is green by the logic we did earlier and and we've done the perimeter we have actually got the whole perimeter figured out now in terms of its coloring which feels like a massive step forward um right but now how are we going to make this hang on how can that be three now no that can't be three maybe this could never be three but i've just seen it can't be three because these two cells can't be gray so that's not three oh i think that's i think that's all we already knew that i just hadn't hadn't removed the pencil mark so it's either one trying to remember what the order was i think it was one two and then three or two three four i think i would love to know which of those was correct ah hang about this cell is now interesting this oh wow yeah okay what's that digit i don't know exactly what it is but it's certainly under pressure because in this column look this top clue is telling us it sees three shaded cells in this string of digits but that that is it is itself also shaded so in this column there are four shaded cells that are seen by the vertical arrows in this clue so that gets four from there but horizontally it gets five six seven but it can't be a seven so it must be it must be an 8 i think because it could be a 9 but if it's a 9 isn't the implication of that that both of those have to be shaded so for i mean from a sudoku perspective it could be a nine but that makes both of those shaded because it gets four vertically it can't be seven and it can't see five horizontally because that double shades that so that has to be eight i think but the interesting thing about that is that's saying that not only does it see four vertically it must see four horizontally so one two one of these is shaded now yeah so the fact this couldn't be a seven tells us this number because one of these is shaded this one of these is shaded that's a two and if that's a 2 that's a 3 and that's a 4. this is quite extraordinary so now these cells are 1 6 and 9 to complete the row and that's not a 6. and now one so now one of these is shader one so i don't know which way round that goes but we've got another thing here that we had up there look one of these is shaded one i've just i've gone over an hour i've got over an hour that literally feels like 10 minutes to me good grief um i was expecting this to be a long video though so i'm not embarrassed yet that i've gone over an hour um okay so what do we do now that cell is a bit restricted now because that cell is counting the number of grays in there so it can't be more than five and that cell is looking at these so yes so this cell sees the same thing this cell does and it sees this cell itself so this is one more than this which means it cannot be one so that's two three four five or six now it can't be by sudoku it can't be four five or six so this is two or three and because this is one more than this this is one or two i think so most of this row is green i think that's what this is telling us hmm okay it could be time to start doing some sudoku soon because this region at the bottom must include that cell mustn't it because yeah oh here's something interesting right right in fact i'm not gonna look here i'm gonna look at this column because i've got eight green cells there if that is the 9th cell in a region then i can't put 6 in column 1 anywhere so that is not a possible configuration and yet that would be forced to be a configuration if uh let's use the nine tool if that is a true border then this would have the only way that can build a nine cell region is like that and that with that is that fails because of the six problem so actually that is part of the same region which must be part of that region it would be rather nice if that if this had been a three or something then i would have known what this was so now that we can run that logic exactly the same way in reverse how could that be a line segment in the puzzle well then this one would join down with his friend the four to create the nine cell region and this two or three couldn't be placed in column one so that doesn't work either so that tells us that that is a line say or that this is part of the same region one two three four five six seven eight nine ten right so now we know that this one region and this four are in different regions so that means that the four region because if we try and join them up now like this that's a ten cell region according to the count i just did let me just double check that yeah that's ten cells so now this four could take as many as those cells but it still hasn't reached a count of nine so it must keep going this way and look if i could get this into the same region as this then i would know what this is and this right by the same logic that this must extend because this one region can take three more cells from this column one two three four five six that's only six cells so that cell here is green oh this is so clever oh my goodness me right now look at this three clue that requires two of these three to be gray and anything contiguous is going to create a two by two so we must do that that must be green in order to prevent the two by two that must get out because all greens must connect holy moly so that's very exciting ah yeah now i'm going to carry on going with my this region one two three four five six seven it needs more cells that's got to be green so that extends to there this region at the bottom has got to come to here then it could flood upwards or continue [Music] um that's got to join up here one two three four one two three four five six seven eight right here is something that i think is fair how could this be a line segment let's think about the implications of that because now this a2 region needs to grow so this is green but this four region needs to reach a count of nine cells well it can get six cells in this column and two here so this has to grow but the implication of that is that both of those cells are green and that creates a 2x2 in green and that's not going to work so actually this is not a line segment which means that therefore this joins to this i've now got a 2 in this region which corrects the count of this to three now i said that was one different from this so that is now a two because yeah and that's that feels like a correct logic because they're both counting all of those cells so now the rest of this column needs ones twos eights oh ones twos eights and nines and that looks difficult for eight because eight can't go in those two because i've got an 8 in the corner wow so if i can join this 2 into this region i know that was a 1 9 pair then this would be a 2 8 pair wow okay don't really see what's wrong with that to be honest um sorry i know i've just i've just clamped up it's because i don't know what to do um now come on simon use your brain oh i know what i can do here that is a one now it's only just counting that cell so this is two or three if it's three those have to all be shaded and these two would have to be green this is not a one anymore by sudoku um that's not a two anymore by sudoku i think i'm running out i mean how does this solve uniquely from here is just ridiculous i mean i basically i'm not far off having used all the clues all of the arrow clues oh i haven't got anything in that one oh sorry no maybe i'm aligning or understating how many clues i've actually used this one is clearly seeing two but could see up to another five so this could be a seven which is rather a lot if it was a seven no okay it's not a seven because if it's a seven all of these are gray and these greens will be isolated from the world so actually it's got a maximum count of six so it's six five can't be four can't be three because it's in the region with three and can't be two and we know it's at least two because it sees two so is that five or six really that's quite surprising because that's quite a lot of yeah that's at least at least three of these have to be shaded four being shaded would be a massive restriction on these greens how could that work no no i'm going to reject that i do not think that can be a six because if that's a six one two i've gotta make four of these five cells gray in a way that doesn't cut off any greens but remember one of these is gray so let's just i don't think it matters which way around we do this let's just do it this way round let's imagine it was this way round and now we're set up we're setting ourselves the task of putting four greys into these and not isolating any greens so clearly that has got to not be gray because if that's gray i've isolated this green now the rest of this has to be gray and these greens are isolated and that logic must work um sort of the other way around mustn't it so if instead we make this one green and this gray then this clearly has to be green or this screen's isolated and now all those have to be gray and these two get isolated so this is right okay well it's right and it's wrong this is not able to be six that is a five and i sort of feel and this might be incorrect that that's going to make this cell gray because if this cell was green i think i now run into exactly the same problem with having to make three of these gray and with with one of these being gray as well i'm always going to be cutting off i'm always going to be cutting off greens it's the same logic so that now is grey to avoid that logic applying one two three four five six seven ah bobbins i was hoping to get to grow this this region here but i can't so where now where on earth do i look now this must be a weak point in this puzzle somewhere and it just doesn't seem to be or to me at least it doesn't feel very restricted this arrow is the only arrow i've not filled in a digit on let's check this one so it sees two oh actually okay it can't be massive can it one two oh yeah yeah no it really can't be massive it sees two there and there it can't be three it can be four but only if those two very specifically were gray and it can't be five because then three grays here would cause two by two problems so either this is two and all of these are green which would be massive because then i'd have a gray region at the top of the grid which is a luxury that we haven't even been close to yet or this is a four in which case those two are gray so this is always green and if both of those are gray no that doesn't work it doesn't work right if both of those are gray how do i get how do i get this clue to work because i've got to put another gray in here we'd have to go there and this green's isolated so that's nonsense so that means that this is two and if that's two we're away because now these cells all have to be green because we've already reached our count of grays in those two cells this is massive so now i've got a region the top of the grid to here must be a nine cell region that doesn't have a one in it yet and that one must go there wow so this is this is it we've got a we've got a region here ah right that cell's not a two now by sudoku so that cell the two in this top gray region goes here which is on an arrow so oh ah nearly nearly oh that is a 2 now that's a 2 and that must be grey in order to make this clue work but also this column now has an awful lot of green in it because it can only have one more gray in it so a lot of this is green hmm i can't see what that means um can that join there or is there some problem with that that doesn't work actually weirdly this is not part of this region not for a sudoku reason i don't think there might be a sudoku reason but that's not the reason i've seen if these join together in a region then these three cells have to join this region but this is already a seven cell region so that would make a 10 cell region and that's not gonna work so this two and this one are in different regions which admittedly is probably not the most profound thing we've ever discovered in our lives [Music] so let's just take a step take stock of what we know this column has an awful lot of grays to put into it this row has an awful lot of greens to put into it this column has an awful lot of greens to put into it and this row has a relatively high number of grays to put into it which presumably means there's some sort of weak spot here related to those things we can't do any sudoku with oh hang on i want to double click digits ones yeah twos got relatively oh we have got quite a lot we've got six twos in the grid right okay where does two go in the bottom row i think it can only go here let's just just check that again it can it can only go there that's a two so this is not two this is not two this is not two ah this is lovely right now that cell cannot be in a region with this cell those would be in the same region so this has got to extend one two three four five six seven eight oh is it really possible for this to be gray i don't know but that is definitely this is a separate region so those two are in the same region um i can't quite see what that means it means we've got to put five in the bottom row where's that going it can't can't repeat in its own region so it's in one of those two cells along with this digit which must also appear in the bottom row so those cells have got to be from one five and nine and that's not a one by sudoku so this is nearly interesting now if if that digit yeah okay if that digit is in this region this has to be a six because it must by the law of leftovers these three digits are those three digits and therefore this one is mapping to that one and it would have to be a six but if on the other hand this takes this cell instead what's the constraint then nothing i don't think okay all right not sure about that so let us instead wonder about well this feels difficult to me i can see that if that's gray then i've got to avoid a checkerboard so that turns gray as well so that isolates one two three four five six seven so this would then become a region which means that this one two three four five six we know it doesn't join here is there anything wrong with this the answer seems to be no um no okay i can't see what's wrong with that so this could be gray wow okay blimey where do we look next um this column has got what okay one more gray to place in this column ah oh no okay oh hang on a minute let me think about that let me think about that so that's gonna lock in a region here two three four five six seven eight nine right okay this cell is not gray for a horribly difficult reason if that was gray all of these are green which means this is gray and we've got to connect this region up so all of these would turn gray and i think that those cells added together are ten cells one two three four five six seven eight nine ten they are 10 cells so that does not work that is green so i suspect there's more we can do in this column that's my feeling but let me think about this okay uh i can put one more gray cell down here and then the rest of it has to be green finding it very hard to visualize where the problem is with that so if those if those were green i'm always ending up with this cell being forced to be gray if i make this green because of the avoiding a two by two rule so i'm always ending up with sort of a region that has to come around like this which is a seven cell region which can never join up with this region which is a bit weird so when this is green i've got to allow this magnet to get out this is green i've got to allow the magnet to get out yes okay so i think that cell is green let me show you why if this sells gray those three cells are green let's do it those three cells are now green but now this is gray this is gray and this is gray and therefore how do i build a region here this this region needs to connect to something so it's going to come to this cell but this cell needs to connect something so they're both ending up in this cell which means that gets to be a region and that's our 10 cell region again which is wrong so that cell is green ah what's this one oh no this ah that's not what i wanted there i wanted that to be i've got two greys to find in this row two greys really don't think we know very much at all about which way they go do we um okay okay sorry so the i'm sure there's going to be a a simple not a simple but like a relatively straightforward way of working this out i'm just not having the inspiration i need to probably getting tired after 1 hour 25 minutes okay so how do we make more progress from here an awful lot of this column at least one two three possibly four so at least four of these cells are gray at least four possibly five right okay so how come how could that ever be green that can't be green because then i have to make all of these gray one two three four five six so yes i have to make all of these um gray and now how does this three get out remember avoid a two by two so let me do this slowly all of these turn gray this including this one this is now gray because we have to avoid a two by two and this is i've trapped a green region here so that's not right so that cell is gray right so here's something here is something okay so earlier on we worked out these two weren't in the same region and that's because it caused a problem down here with the tensile region so if these two are not in the same region how could this not be green if this is gray this region this two region cannot join to this region so it needs to get out so it's going to have to come here but this region can't exit it's not a nine cell region even if it takes all of these cells so it has to come out to here and that means we get this pattern and both of these are green and we've got loads of two by twos going on and that's not gonna work so what we can say is this cell has to be green and it has to be part of this two so this is a region starting to grow now i reckon we might have to do that again for this cell um let's think about that if this cell was now gray this region has to take this cell and it's the same logic one two three four five six seven eight yeah it's the same logic so that's also impossible that's got to be green and part of the two region now oh now it might not work again because it looks now we could go in here unfortunately so if we try this again no we haven't we haven't penned ourselves a rotten rotten thing um so we can't quite finish it along those lines right okay um so what is it then what is it we're meant to do here i'd love to know which direction this went in right which clues have we now i've thought a bit about this one i can tell that an awful lot of this column now has to be the same color so if that was green all of the if that's green all of these turn gray this then would join up here that would be a seven cell region don't know one of these is gray one of these is green okay i've got to find two more grays in this line haven't i so and that's out of four cells so two of these four cells are actually green as well do i want that to be green i don't know i'm not sure or do i want to look at this column again there's only one gray to put in this column so if that's the gray all of these turn green let's just have a look at that for a moment if that's gray all of these turn green and now this has to join up with so it has to be a one two three four that has to be a nine cell region like that but we wouldn't know what this was don't actually see what's wrong with that to be honest um hang on hang on maybe we can disprove the alternative then so if on the other hand this is green we looked at this a bit earlier feeling it creates the wrong count over here with this magnet region again because one of these is now gray and one of these is green so if this is green that is definitely gray this is definitely gray because we need to get this to a size of nine that gets us to a seven cell region which cannot now join to this ah that's it that's it because th this seven cell region can't join to that and that means we need to get both of these regions out through this column we can pick up one cell here we're making this an eight cell region but we still need this cell to be gray whereas this one also needs to get out and only one of them could get out because i can't make both of these gray one of these has to be green so one of these gets blocked off let's make it that one and show you the problem that's going to connect these regions the alternative is that i allow the magnet to escape but now this cell has to be green and this is isolated so this is it this is it it's beautiful so actually let's come back to this digit i'm not digit this cell this cell has to be gray and therefore these two cells are are green and therefore these have to be gray to create a region and this region one two three four five six seven eight nine is we have a region that is a region of sort of funny question marky shape whoa whoa whoa whoa funny question marky shape region in the middle of the grid um that might be some opportunities to do some sudoku stuff with that perhaps i'd love to know what this was um if that's gray what's that doing to this region once oh no no no this is magic this is magical look at this region this seven cell region at the bottom is now seems to be penned in so i can build it i know what this looks like it looks like an h uh it's got to be nine cells one two three four five six seven eight nine it's now nine cells so this region one two three four five six oh bobbins it could just go all the way along there or it could dip down through here we don't know which it does if it dips ah no we don't know what it does okay but what we can presumably do now is to think about these cells um oh the simple thing to do in fact is to note those cells cannot be twos and threes so when i'm putting twos and threes in this column the answer is in this region and there's a two here so this is a two this is a three those these squares are now six seven and nine we're going to get this digit that's going to be a one wow wow wow wow wow six seven nine imagine imagine how jasper must have felt constructing this look like when you got to this point it must be so exciting i've been thinking maybe i can i can actually do this and it will it will fit together um okay so now now what now what's the next step so now this is correct and and done we've got is it this region is there something going on with that region i've got to put a five in that region five's got to go in one of those two cells i don't know this grey region has to get out but i think it's got opportunities to do that it's got two ways of exiting from the little cul-de-sac it's found itself in so okay there must be something else ah there's two clue now i've got one of them so one of these is gray exactly two of them are green ah i've got five here i've not thought about this for a while one oh okay i've got a count of oh hang on this has got a count one two three oh okay sorry let me just think about this i've got a count of five so i've got to put two greys into these three cells now how could those both be gray if those are both gray then this green cell how's it ever getting out of the corner because one of these is gray so it's getting penned in whichever one of these is gray so those are not both gray that's grey now does that tell me which of these is gray or which of these is grey yeah what so one of these is in one of these is out it's the same as this oh no two i had two arrows going the wrong way um oh okay this cell now which is a green cell because one of these is green only it's building a region vertically it must be going up here [Music] i don't actually think that's very interesting um so one of the i don't really know how to like yeah okay that's how i'm going to do it i'm going to draw little boundaries one of these is gray one of these is green one of the these is gray one of these is green which presumably means something what about here then i need one more gray in these cells oh yeah and the other thing i've not thought about for a little while is this clue which requires an awful lot of an awful lot of grays in this column so if that's green ah i can't quite get my head around this what at the moment i've got one two three four possibly five so at least three of these four are gray at least three possibly all of them what about this one then can we can we somehow say something about how this needs to grow so if it comes this way then then it's blocked in here isn't it so then it's got to go up in one of these positions that would be grey you have to go up like that oh no it can't no it can't go up like that that's gonna break the oh right okay hang on hang on hang on this cell's ability to grow is impinged upon because it can't come up this shoot because there's too many grays required in this column so how does this three collect its friends how does it connect to its friends it cannot come through this this tube here because then this eight clue is impossible so it must come up through this tube those and therefore these three cells are in the same region which is maybe interesting so now oh yeah so now there's two clue now that's a boundary one one of these is green one of these is gray but we still don't know how this two grows mary mary quite contrary how does your green garden grow i don't know i've got a horrible feeling it could be sudoku ones let's just take a stare at this for a moment or two in case there's something i mean i haven't pencil marked sort of these cells one of five options just because i'm allergic to doing that um twos oh oh i've got eight twos in the grid oh for goodness sake right where's the other two is that i'm not put two in this row uh two is going there oh good grief right that's massive that's massive because now this oh good grief right okay how does this two grow oh this is this is just so clever wow okay how does this two grow now the answer is we don't quite know it can come along this row for sure and that would get it to a count of six if it if it came along there we know it we know it doesn't join up with the one in the corner so it could get a count of six it could get this cell that's a seventh but it can't run into these twos so it's gonna have to come down eight and it's gonna have to come into the three whatever happens it has to hit the three so now i've got a seven cell region in this column i'll yeah now now what cells this is because because that seven cell region means that's green so now this is a region one two three four five six seven eight nine and that that means i can put a six here by sudoku i've got to put a six in this column it can't repeat which means that's an eight or a nine i've got to put one in this region it's got to go there and if there's a one there we know it's corresponding to that being a one don't we by the laura yes i've got to put one in this region yeah in fact everything's getting forced everything's getting forced because this region's only got eight cells so it must take that cell as its ninth and that's we know that's going to be the six that goes that can't otherwise go in the region so that's a six oh my goodness me oh my goodness me this could be it now now now look this has to be five this has to be one to correspond with this one these digits are now three four seven and nine well uh three four seven nine that's not three that's not four oh bobbins i knew i shouldn't have started this this this profligate um pence marking this six means that's a nine by sudoku so this is a one now these digits maybe three four eight nine no no i'm going to resist pencil marking that just for fear of this getting very cluttered very quickly um okay but now this is a seven cell region so it could reach as far as this cell but it can't reach as far as this cell so this cell's region must join its friends over here so that is a region one two three that's up to seven now so it cannot join this region because if it if it starts to come down now if we made that that link it would have to hit this and become a 10 region so it must take another cell but his last cell is either this one or this one we don't know which or i don't think we know which um okay where okay here's a question where does this region get its one from because it hasn't got a one in this column it can't be that cell because there's a one looking at that cell and it can't be so it's either got to be something in this column i don't think it can get to this column or it's got to be this cell how does it get to that column it can't there's no way so we've got these x's that it can't move through so that's got to be it that's got to be green it's got to be in this region and that's that's done it has done the puzzle it's done the puzzle because now this region i've got one two three four i need four more at least so that's an eight that's a nine all of this turns gray and therefore that's green by yin yang that's green by yin yang 234 this looks like it's a region here actually not certain about that but one two three four five six seven eight yeah i think that's gonna join this with that one two three four five six seven eight nine over c yes no the simple way to do it is to notice that this region needs another cell now and that's got to be there so that's a region and that forces this to take this cell as its ninth cell so that's a region which means that now we've got this green cell at the bottom region at the bottom which is of size nine at the moment so it can't grow any more which means that cell must be gray and that i think somewhat extraordinarily is the shape of the regions done isn't that extraordinary that's a nine by sudoku where does nine go in this region where does no where does nine go in that region i'll tell you where it goes there how many nines have i got now let's keep oh that can't be nine um let's keep thinking about nines for a moment nine in this three region can't go there can't go there so it's in one of those two cells i'm not sure whether i can limit it further but that means that's not a nine at the bottom of the grid that's not a nine at the bottom of the grid that's not a nine at the bottom of the grid which means that is a nine which means that where does nine go in the question mark region it's got to go there i think which is knight goes here it means nine is not there anymore oh bobbins i thought that was going to go all the way through that would have been so exciting uh how many nines have i got though i've got seven there's one i've got to place over here right where's the other one and wouldn't it be awful if i find that i've made a mistake no okay nine in this column i've not put in i think it's got to go here by sudoku so that's a nine which means that's a nine and i've done all the nines there we go so it's possible that this is not going to be a monstrous um a monstrous irregular sudoku now i'd be very pleased i'm still under two hours i'm still after two hours that's not awful um okay where should we look next is there somewhere obvious that we need to focus upon possibly um i'm trying to spot law of leftovers type things and failing miserably okay there is something what about those digits what are they what are they yes okay i think if we look at these cells 1 6 8 and 9 can't go in those cells in in this three shape region so one six eight nine have to occupy those cells we've already got the nine so this must be a one six eight triple and six in that triple must go there look by sudoku of all things so now now six in this funny shape region is not in those cells or those cells so it's in one of ah so it's in one of those cells which means that six is not here that's seven that's six so what do we ask now perhaps about six in the question mark which has to be one of those two cells i think not sure if we can do better than the oh well that's quite good because that's looking up there and giving us a six here which is at least a little bit interesting um [Music] so how many sixes have we got now lots seven so we've only got two more to place oh i see but it looks like we have an option there so we have an x-wing of sixes left in those cells what i could do actually you know which might be sensible is to get rid of the lines through the regions because we now know the shape of the regions so it might make it easier to scan if we get rid of the the green lines maybe like that oh and i want to do the edge down there to make it look oh and the edge up here to make it look like it's symmetrical that makes me feel better okay now more sudoku where do we look next what about those cells three fives and eights um three five eight that's not able to be eight that's not able to be three that's quite capable it's not able to be five actually so we've managed to limit those to one as well effectively binary positions but that's not quite good enough is it um [Music] i've got a one here therefore that seems to have to be an eight that gives me an eight and a one here which is better so these are now no longer eight which makes that sell an eight by sudoku and i get myself a three four pair in column nine maybe i double click my eights now and see what we can say about those i have got six of them so is that good enough the answer is i don't know nearly eight in this column is really restricted it's in one of two places eight no it's got a i think eight's got a few options in this column yes i'm missing a trick and then eight in this column has got two options again i think it's those two cells bobbins okay so maybe it's not eights that we have to look at it's going to be some other naughty digit what about this column i've got lots in that column three five and seven so that's a five or a seven this is ah that's a five or seven so the threes might be yes so that gets me a three at the bottom of the grid and a four seven pair here let's double click our threes and see if we can see anything interesting with those um not immediately or am i am i doing myself a disservice yeah i am a bit actually where does three go in the question mark well this three and this three tell us it goes in one of those two cells which is actually pointing at that cell and making that an eight and that means this is a five which i think means that's the eight in this so it also means this is a three but let's just check where eight goes in this region now yes it has to go here which takes the pencil mark of a six which means that's the unwinding of the six x-wing and now these two squares have to be four and seven which gives us an x-wing on fours look so four in the three region now can't be in this cell must be in one of those two um threes and fours oh this must be about it must please tumble now please tumble um please tumble before my computer keels over with the length of this video gosh imagine if i imagine if i had a crash now i don't think about that don't think about it um four five seven into this square so this is four five this is four five or seven bobbins i think everything's possible there isn't it all right this column that's got a lot of real estate in it fours fives and sevens let's put the options in and see what we can get rid of yes we know that the fours are an x-wing in those cells so these can't be fours so that's got to be the four this becomes a five-seven pair which is in this region which means we still need to put one and three in this region so that's got to be one and that's got to be three how many ones have we got loads all of them okay that would have been a quicker way to work everything out so this threes now we've got seven threes so we must be able to get the rest of the threes surely where do we need to still put threes we are we need a three in this row and it can't go there so it's going to have to go here so three four four seven go into the grid that fixes the seven five pair this is a five by sudoku this is getting exciting um we need what do we need in this region five seven and eight that square has to be a seven then and that's got to be the eight let's double click the eights that's all the 8's done and this 7 gives us the 7 and the 4 at bottom that knocks 7 out of here so this column needs 3's 4s and 5s and that has to be three and that has to be five and that has to be four therefore which means that's seven that's four please it does look right it looks right with the seven there it does look right it's i don't think i've got a repeated digit anywhere good grief um do i dare click tick i'm gonna do it yes wow okay that was very very very hard two hours um [Music] jesper take about how did you come up with this i mean that i have no i actually have no idea how you make a puzzle of that complexity because even once you have the thought about it the start was really difficult to sort of pinpoint how the the edges worked but even once you did that imagine you've embedded clues that allow you to build all the sudoku regions work the yin yang out and then do sudoku off the regions you get it is it is absolutely the correct adjective to use genius about that that is something quite exceptional one of the greatest one of the greatest puzzles frankly that there has ever been made full stop and if you think you can come up with a better one i look forward to the comments because i think you'd have to go some way to justify a puzzle that is more impressive than that wow wow well thank you so much for watching if you're still with me now this is a movie length episode by all accounts and with that i shall go and have my lunch thanks for watching back later with another edition of cracking the cryptic [Music]

Channel: Cracking The Cryptic

Views: 93,391

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Id: N1Fi3xt3NkY

Length: 119min 1sec (7141 seconds)

Published: Wed Jul 06 2022