Waiter, This Spaghetti is HARD!

hello and welcome back to cracking the cryptic and another sudoku puzzle today so not talking about competitive strategies like yesterday i'm just going to try and do a puzzle that's been recommended um to us from our discord server this is by jovi al and uh it's basically an arrow anti-knight puzzle so um i guess knights might have used arrows in the old days but uh we'll look at that in a moment um first of all arrows today very relevant as we have now taken the decision to make our next app an arrow sudoku app so we will continue to update all of the other apps until they have 100 puzzles within a year that's kind of how they all work a couple of those have already completed their 100 but the others are still ongoing and they have quarterly updates normally now so that's how they work again when we get around to launching arrow sudoku and we first got to commission a load of puzzles write a load of puzzles test a load of puzzles hint a load of puzzles so it's going to take a while but when we get around to it there'll be 40 launched initially and then three more quarters of 20 each so that's how it works um don't expect them any quicker than quarterly these updates although i know a lot of people work through the puzzles and uh and can't wait for more so that's always great of course and the the links for the existing apps are on are under the uh under the video in the description field so also there is the link for this puzzle also there is the link for our patreon site where of course uh we have loads of extra content every month and we're coming up to the beginning of february soon so there will be a yeah it's a kind of triple header i think that's probably what we'll be presenting for february now i do want to congratulate the people who've finished reverence puzzle hunt since the last time i read out names slowed down to uh less than two a day now entries coming in but well done to those who have worked through it peter somhost matthew brockwell sophie and conrad hannah salter travis and rachel rochelle r and misha and his mum myoko well done to all of those um individuals and pairs who have got through that puzzle hunt whether or not in lockdown at least it's something to do so well done to you now this puzzle um the rules are very straightforward for anybody who knows either anti-knight sudoku which is where this identical digit can't be a knight's move apart so this digit here couldn't appear in any of these eight cells for instance and arrow sudoku in which the number in the circle is the total of the numbers along the arrow normal sudoku rules apply and that's it do give it a go on the link under the video it is highly recommended so i'm looking forward to this and i am going to start now so let's get cracking um yeah there's a few arrows with some length and there's this intriguing trident up here what is this doing um well i mean the absolute it can't be six because there are four digits along some of the paths there the same is true for this and this arrow they must be seven eight or nine because three digits must add up to at least six and then there's another one ah i have a feeling the possibilities are going to reduce dramatically because of the difficulty of repeating digits yes okay that's the way to look at this there must be a repeated digit on this arrow for instance because it doesn't add up to ten and one two three four does add up to ten so it can't be one two three four i'm not saying you can't have a four or a five in it i'm just saying it can't have four different digits therefore it has digits that are the same now which two can be the same and this gets very interesting with the knights move this one could be the same as this one but it can't be the same as that one which is in the same box or that one which is a night's move away this one sees all three others in the row or in the box this one sees all three others in the row or by a knights move so there is a repeated digit on this arrow and it has to be in those two cells so i'm going to color them the same has got to be true this is a symmetrically opposite arrow diagonally symmetric i suppose but the same is absolutely true this one sees all the other three and this one sees all the other three so the repeated digit has to be in the green cell now can it be can it even be a two if it was a two these would have to add up to at most five i suppose they could be one three and one four no they couldn't be one three and one oh that's very interesting right look these three cells see each other and that's crucial right yeah this is the right question if these were all two and it's going to get worse if they're three or higher but if they were all two these two cells would let's assume that's a nine for a moment the maximum these two cells would have to add up to five and they can't include two so they must be one and four but the same is true of these two cells because this total is nine they're one and four and that cell can't be the same as either of those one in the box one on the knights move and therefore it's just not possible now i'm going to put in the digits to explain this and i've only tried it with nine in the corner to start with but it'll work exactly the same with eight so if they were two yeah sure it looks fine for this arrow you can have a one four pair here but here you need a one four pair again because you've got four already you need this to add up to five it can't include a two and yet this can't be a one or a four so that wouldn't work the same is true if this was eight and this was a one three pair you've still got the same problem they've still got to be one three to make this eight and that means that these cannot be two the same would apply if they were three um this would now have to be nine this would be a one two pair and again you can't put a digit that'll make it work here so these are not two three or anything higher they are one now i don't know that this is nine yet although i strongly suspect that it is now these two now have to add up to seven which is a much bigger number there's a lot more freedom but still this is different yes these two well it might be seven it might be six it might be five but those two have to be different from that even though these two are coming to the same total as the horizontal pair so that has to be the same total as that but this has to be a different digit so yeah that it's got to be nine and these have to add up to seven if they were six even that's kind of the next maximum number they'd have to be two and four but again these would have to be two and four you need more freedom than that so i don't know which way round they are but i do know they add up to seven that makes this corner nine which was what i always suspected but we've proved it now now ah look oh this may be maybe i should have seen this before this cell sees all of these by knight's move or sudoku so it can't be two three four or five does that it can't be seven because that would have to be one so it's six no no no it could be one you can have repeated digits on the arrows i hope i mentioned that at the beginning if i didn't it's in the rule set um this must be a seven or a two that's right i think can this be a two yes because it can see either of those cells fine um it can certainly be a seven and because this can be a one there's no problem with this so i think unless i'm missing something with the knights moves that's as much as we can do here for now now but let's use this where do we get the repeats principle on the other arrows what about this one yeah look this one sees all of the other three cells on the arrow so does this one in a much more obvious way that we don't even need nice moves for that um but the point is they are not the repeats these are the repeats on this arrow now they obviously could be ones if they were twos ah if they were twos yeah there's no way i don't think because of this total if these were twos these would have to add up to three four or five without using a two and how are you going to do that when neither of them can be one you can't and the same is true if this if these were threes in theory that could be two one but neither of them could be one so these oranges are one again one seems to always be the repeated digit and it doesn't help us decide what this is at all because these could be two three they could add up to five six or seven basically okay let's have a look at this one where's the repeated digit oh this is a bit different this is nice that's not the repeated digit that can see them all so in the previous two arrows the repeated digit was at the beginning and the end of the arrow here it's not at the beginning and it's not at the end because that one by knight's move can see that and by regulars today you can see those so here the repeated digit is not at either end it's the two in the middle so another color for those um it's not one is it so it's two or three where am i now so it's two or three would three work yes in fact we've got to have a one on the arrow and we know exactly where it is now it's got to be here and then this can be 361 if that was threes this is a two but if they're twos two four five it can be three or four and still make this okay hmm okay that's interesting ah if they're twos though which i thought was far more likely because it gives two choices here and this can't be seven anymore by the way um but if they're twos that's hard here isn't it then this has to be a three four pair oh look we've got a one here sorry uh scanning across that now that has to be a six so this is two so two's not in there five's not on the ends of those arrows there's a 5 2 combo in one of them oh and that's very interesting if this is 2 and this becomes 3 4 there's a three or four here so this now has to be five two and where does the two go in this box look if the blue cells are twos they're all not possible and now you've got two there and two in this one stopping those my goodness that is intricate and all of that means that these blue ones cannot be two because you couldn't get a two into box three so they are actually threes which is not what i was expecting makes this a two makes this a nine this isn't a nine now so we've got to have a two on these on this arrow to either get to seven or eight yeah this adds up to five or six two is there and now we know this is the 3-4 pair and this is the 5-2 pair and we can fill them in oh this is so clever um this ah no this is yes this can't be five now because of that oh it never could be one three four i can't do my maths it's three or four we know it's not three so it's four and this is eight good grief what a wicked puzzle it's absolutely brilliant now how do we make further progress we've got twos there so twos in one of those now we don't have any more four cell arrows to work on they've been fun but that fun is over we have this which and this actually um this can't be a six because of the knights move so it's seven eight or nine and it's picking up three cells in the same box as is this one probably still can be six can't be eight now we don't know much about limit oh look ones are limited to those two cells twos twos up here oh look by knights move they rule out those so we can place two on the arrow unsurprisingly that puts two in one of these two so that's a one two pair nine can't be in those cells or on the arrow or for fairly obvious reasons you can work that one out um doesn't really do anything and two pair now what about ones and twos then we've got so one over here is in one of those two cells ah this is this is a classic oh yeah this is a classic um knights move position both of those cells see both of those what do i mean by that well i mean if there was a knight here a one here it would rule one out from both of those cells because of the knight's move constraint if there was a one here it would also rule out one from both of those cells so those cells cannot contain a one you could actually ask where in row seven can you put a one now and clearly the answer is here and therefore that must be a one and what that does is also puts a one in one of these two cells because those two were ruled out effectively now there's almost certainly a one on both of those arrows because otherwise the one misses them both then they both have to be two three and four these two cells would both have to be nine is that possible that be a nine here here here and then an x-wing of nines there and that is possible i thought i'd be able to rule that out i'm sure the ones are going to be here but i can't prove it yet so we'll we'll come back to that now yes these positions for two again oh no i was gonna say they rule out two from here so where does two go in the column but it could still be there and it could well be on the arrow it's quite likely to be on the arrow again if the ones are on the arrows as i think they are that is going to put a two on the arrow but i don't know this for you for sure yet are threes though that's a three because we've got that three four pair um what does that do not much oh we're running out of easy wins here which is a shame oh where does three go in this box it's quite an interesting question that three sees those two cells by night's move and those by ordinary sudoku that's clearly not a three and this can't be a three because of the arrow that can't be a one so three is confined to one of those two cells and that means it's down here in one of these ah oh yeah look where does it go in the central box those threes and that three are ruling out all of those this three is ruling out those two by the knights move so it's definitely on the arrow um so the arrow is not a seven one three four though is possible or two three five so these cells are only from three four and five this one sees a four by a knight's move ah and i still haven't decided it haven't ruled out two three four doesn't really get much done oh okay what else can we do that six can't be in either of those cells so six in row three i don't know somewhere up here i'm probably missing something very clear oh this is an interesting one it can't be one two three or four and yet it's on an arrow so it's clearly five six or seven i'm not going to put eight because that would need a one here which is impossible so in fact yes one and three are impossible here and nine's impossible here so this is definitely a two it's the only way this arrow can work this is seven or eight it can't be nine so that can't be seven this six actually sees all of those cells as well as that one so six is confined up there ah and six is confined to those three cells so this can't be six this is another classic knight's move position those three all see this one two of them by knights moves one by regular sudoku so they stop that being a six because there's one three in one of those positions that's intriguing now four can't be there so four's in one of these spots can this be seven no now if look at that now it can't it can't because four is looking at that cell and so is one and two if this was seven this would have to be one for two that would have to be one of the digits and it can't be that's brilliant so that's a nine which doesn't solve anything else it puts a nine in one of those two cells again two three four remains possible as does one being on both of these oh that's intriguing um crikey what next what what are we gonna find in this puzzle next there's so much in it it's so clever can this be a six actually that would put four here three four yeah it can can't rule that out what else can this be um this one is not very constrained only tiny numbers 108 can't be in it so it's five seven six sorry five six seven or nine that makes this one three four five or eight and i can't see why it's not any of those that's not very helpful at all and that's the last arrow that i haven't well okay i could look at this one a bit harder so this is now nine we know that so if it was 2 3 4 ah yes the 4 so if it was 2 3 4 it would have to go 4 3 2 which would put one here but it might have a one on it which is the alternative to being two three four the one would have to be here because of where ones can go in the box to get on the arrow and then this pair could be six two or three five i suppose in any order irritatingly that didn't really get much done but at least we've got all the candidates marked on the arrows i don't know maybe maybe it's maybe it's been a pointless exercise but i like to get it done if we can um now what am i missing what am i missing that can't be four that's not very interesting i have six or seven there haven't got much done in terms of five sixes and sevens at all in this puzzle i mean we did a little bit with sixes here that does mean six can't be in this cell doesn't it yes if six isn't one of those two they both see that one so six in box nine must six and column eight is what i'm saying must be there so six in books nine must be there um if that was six it would rule six out of there if that was six it would take it out of there that's not very helpful oh this one sees eight nine on the knights move ah it sees nine on the knights move so i should never have marked it as a possible nine nine must be there so that's not nine and that's should never have shown eight i should have put seven in and taken it out now so i've done that um careless pencil marking again six seven or eight here ah now eight can't be in either of those positions so eight is in the top row there and therefore it's down here in row in column one and one of those cells oh and it runs out of information interesting though um yeah so six being there and that felt like a breakthrough but i don't think it really was necessarily ah that can't be one three four two nine or eight again that's five six or seven this one can't be three four two one nine six that's five seven or eight i'm not seeing any pairs and quadruples breaking here oh frustrating um right what do we need to concentrate on next i mean what a puzzle gift that keeps on giving it's not letting up at all really is it three four pair is that not they both see this cell so that can't be two six one eight three or four that's not very helpful either five seven or nine i still can't decide on this wretched um eight or nine so what if six was in one of these cells really help much there's there's too many possibilities for six elsewhere um okay what if this was six then you'd have no i don't know that doesn't really get anything done oh what's the right question at this point i do not know this is tricky stuff this 2 so there's a sort of trident of cells there and those can't be 2 and that's not 2. so 2 in column 6 is in one of those two spots now actually of course this is a one-two pair so twos are definitely distributed in those places in columns four and six they must be there so oh yes two is clearly in one of these two as well just by regular sudoku there but they don't sort out this pair at all how infuriating um oh goodness where should we turn sorry if you can see something that that i should be spotting here this feels very tough to me at this point again well maybe maybe i now think these are four three twos along the nines but i don't know i thought they're either gonna both have ones or both twos here yeah depending on what that is that's making both of these ones or both of them twos does that help as a thought i can't see how i must say goodness me okay what if this was eight then eight would be here that um that's quite poor well now it doesn't change what we know in box one it doesn't really change anything oh my goodness sorry about this folks let's just keep concentrating and try and get something to break out of this puzzle um i am finding this tough now as you can see oh that three four pair sees this cell now that's a bizarre thing to point out but it does make it six seven or oh sorry that makes this one six seven or eight and that three four pair makes this one six seven or eight so we have a definite three four pair in column three ah six can't be there or there so six in column three is down in one of those cells and that is a very difficult combination for the sixes to maintain and i'll tell you why because a six in either of the middle cells there rules it out of the three cells it must be in in the other column so six cannot be in the middle cells therefore it's a little x-wing of sixes and the six in row eight now has to be here on the arrow goodness me that's hard to see well it's hard for me to see but we've got there now five or seven there that's not eight it's five or seven eight is there which was what i was just wondering about got a five six seven triple that doesn't help that's not eight oh and is that it does the whole trail run dry again four five and seven down here no that's not fair i was so pleased with that but i just don't know whether that's six or seven does it depend on whether that's no that could that could be seven oh my god six is only in two possible positions in row three if this was a six then this would be a six in box four this would be the six in box three that would be the six in box two this would become the six here and that clash no that couldn't be oh my goodness there's nowhere if this was so where did i start where did i start i said if this was the six no where does this start this is an impossible arrangement of sixes but is yes it was in row three if this was the six in row three then that forces this six because between that six and that six they see everywhere else in box four it also forces this six in box three and between the two of them and this sorry this six that was already placed they rule out all the possible positions in box six for a six so that is not the six in row three good grief this is the six please do not peter out again like a useless deduction um although i think it might immediately we get a five seven pair here no that's a lovely deduction because they can both see this cell by that one by a knight's move that one by regular sidokin they must be different so that can't be five or seven so we can fill in our next six take it out of there it's on the arrow that's a four that fixes oh my goodness this was a whole sort of deadly pattern of threes and fours but not deadly because they're on the arrows um oh wow does that help or does that not help my good grief please don't tell me that stops again here six sixes let's see where we've got sixes um oh yeah no one of those oh look there's a six there so sorry six is placeable in box six and now it's in one of those two cells in box four which is not quite as helpful as i wanted it now four five and seven to place here in box six this still is not giving up what a puzzle um four two six three that is five or seven oh they can still both operate together ah no look where does five go in box two in one of those two cells what do they both see they both see this cell on the arrow surely that helps now three there so this can't be three it doesn't resolve whether this is four one four two or five one and whether this is eight or nine that's so unfair i feel like crying right three is in one of those two positions it's not here anymore but we can still go two three four to make the nine or one six two or one three five i haven't haven't taken any other candidate out three in box one is down in one of those four sales that's not very interesting still got more to do this is unbelievable every you know every deduction feels like it's a huge step forward and it's the absolute opposite five can't be in those two cells because it's placed here so in the middle row five must be in one of those three that's hardly interesting it keeps five out of that cell that's nothing else um six and three are in those two now two and one still no no change in the ones and twos ah five seven pair in the top row sorry okay six there not six there let's take out the corner mark because it's annoying me now seven eight pair there um yes six here not there that stops this six because of the night's move okay so we get these sixes and now this cannot be a one six two um nine sum so it's either one three five or 2 3 4 so this is definitely a 3 now is that right is that right is there any way this could be a 5 no that's a 3. that's not a 3. let's get rid of three from those um the three in box four is not in that cell because both of those can see it so it's in one of those two which i thought was going to help me here but that's just an old pencil mark that hadn't been removed yeah basically i'm down to those for my last threes that's can't be resolved until something else is now how about this nine seven eight six one two is below them three's in one of those two now i can't see how to use that the one two pair here we've got a little more in the row since i first found that in the column i mean um oh my goodness i mean maybe my brain is just fried by this puzzle that might be the case seven eight i missed that five seven pair working in the top row for a long time so i could easily be missing something else working hard up here and telling me how to resolve something in the top of the puzzle that seems to be the most likely place four four is not just not a helpful number in this at all down there very slightly so how about if this was four then that would have to be four that would be four that would be four and that would be four and that's fine if this was five oh that would be five that one this one oh that one there there don't tell me that works as well no it doesn't work because there's nowhere for a five in box seven so this being a five i think what that does immediately yeah it forces the five in box four to be there and it forces because of that five it the five in box eight would be there and between those and the the given five that we have already oh now hang on am i getting this wrong five there five there five there yeah there's nowhere left okay so i mean that's a reasonably complicated chain of circumstance but it exists and that makes this a four which still doesn't resolve that wretched thing but it stops four being there we know four can't be here so that's a four so this is a two that makes this a one and this a two they are both two three four arrows giving nine which at various stages i both was certain of and then totally doubted um it just shows what these puzzles can do to your mind nine in this box is there by regular sudoku good old ordinary sudoku then we have an x-wing of nines here that aren't resolved by knight's moves irritatingly um four is in one of those two cells in box seven no it's not it's not there because of the four pair down there so four is resolved in box seven that places it in box four sure that could oh yeah we've only just put that four in okay so that let's fix the four out over here that fixes the four down here into that cell all the fours are done i think yes that looks right now let's take out this old coloring sorry i've just been ignoring it myself but it may have been irritating others um that is five seven or nine probably has been for a while but i'm going to write it in now and we're still not actually finished here got everything on the arrows i think completely nine six four two three so this one that is placed oh this isn't two anymore that that's very helpful that gives me the two and the three that gives me the three here that's not three now five to complete the column seven to complete the row five to complete the box five to complete the column seven to complete the box five and seven in box three this feels better five there oh that's not five and it suddenly runs out seven and eight to place in column six oh that's not five though so five can be placed and that gives me a five here and there's one more five to do and it must be here and that works fine that gives me the nine which gives me nine here seven to complete the row eight and seven in box three eight and seven in box one eight and seven in box four eight seven eight don't tell me seven eight there we go let's hit the tick my goodness that's a puzzle isn't it what an excellent um arrow knight sudoku really good fun thank you very much to jovi al and to the recommenders i enjoyed that uh sorry if it was keeping you tense for a while when i was missing some of the slightly obvious things i hope i wasn't missing anything else that i haven't spotted afterwards too badly but uh that struck me is pretty tough i'd love to hear what you thought of the puzzle if you tried it in the comments uh i don't love to hear what you saw me doing wrong but do let me know anyway great to be with you again and hope to see you again soon bye for now

Channel: Cracking The Cryptic

Views: 23,380

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Id: j1hVXOEFwSQ

Length: 45min 55sec (2755 seconds)

Published: Fri Jan 29 2021