Thanks for covering these puzzles :) If anyone wants to access the puzzle booklet that is linked to in the description to check out the other puzzles of the contest, the password is pUZZLEsQUARED^2 We'll upload a password-less booklet by tomorrow mostly.
Thank you for the added puzzles, too bad I can't open it on my android phone, beacuse the plugin is not supported anymore (or did i somehow block the plugin?)
@@DavidHsueh you don't need the plugin to see and download the puzzle booklet. Otherwise if you want to participate in future contests you do need flash for now.
@@PrasannaSeshadri16 I'm so dumb, didn't interpreted the booklet as a download, but as a password protected 'game' run in a plugin. And i see it has already been undone from its password. Thank you again
38:03 had me laughing out loud! Instead of using the total of the 35 clue, Simon calculates the 2 digits that must be missing from the row...Of course it doesn't matter much, you get to the same digit, but still hilarious :D Brilliant puzzle though! What a fantastic idea to use those grey cells as kakuro clues
Thank you :) the whole contest was themed on variants of puzzles where the puzzle rule itself doubled up into them somehow. Check it out, link in the description.
@@PrasannaSeshadri16 Definitely going to check it out, although I fear they are way beyond my skills! I love watching both Mark and Simon solve these, and I can pretend to be a bit faster on some digits, although they both solve half of the grid when I am still shouting at the screen :D
@@11mandylion come join our discord group if you haven't yet, try the welcome pack there and join in the discussions, you will quickly become better :)
So, the solution to the cloverleaf puzzle was like finding a four-leaf clover, tearing each leaf and making a wish. You gotta work on each leaf in order. Beautiful!
The intended solution for the clover kind of explains why it was a tribute to ahaupt. It's similar to the trick they used in the infamous "Expert Puzzler Gets Pranked" puzzle.
Really appreciate you going back to yesterday's puzzle. Thought your approach wasn't quite right at the time (not that I could do any better!), so really like that you took a moment to show the true elegance of the puzzle.
Haven't done Kakuro for quite some time. I used to do them in puzzle books and always loved them. These were especially fantastic editions of the style. Keep them coming Simon!
This was my first crack at these kinds of puzzles (and I don't do a ton of killer sudoku)...Puzzle 1 didn't take me too long but naturally I got stuck on the bottom middle section - never occurred to me to do macro-arithmatic to solve it Edit: I almost chickened out of Puzzle 2...But, I decided, what the heck, I'll give it a shot, and I managed to solve it! Official time was over 3 hours, but I got there eventually. That was fun!
Both puzzles were an absolute joy to solve! I nearly made some mistakes here and there, but managed to crack both of them in just under 30 minutes apiece. I especially liked the second puzzle - the gray cells were used in a very clever way in a puzzle that was otherwise fairly low on clues. I would love to see more Kakuro in the future!
Also, thank you for bringing Kakuro! It's the first time I played this kind of puzzle, I really liked it! And props to your solutions, specially the second one, it was amazing how quickly you spoted all that the creator probably intended (it took me a while to get everything, but I'm happy not needing to bifurcate as in the first one).
38:08 shows us a window into simon's mind. instead of just doing the sum of the row to find the 2, he went on a very different way of finding the 2(by using 1...9 sums up to 45, etc)
This was my first time seeing a Kakuro puzzle so I just watched. Very interesting. My way to start the Phistomefel puzzle is simpler and doesn't use a system of equations. Look at the bottom 4 rows instead of the top. Subtract the bottom right box and all the cages. We see the remaining 8 cells sum to 20 and they come in two groups of 4, so they must be two lots of 1234.
28:37 for the first puzzle and 33:08 for the second puzzle. This is my first time to solved kakuro puzzle and it's very beautiful and very enjoyable puzzle! Brilliant!
For those who are reading this and haven't seen the contest PDF that is actually one of the puzzle names and not just bak going into gibberish fanboy mode over the contest :p
This second puzzle is so great! The logic it follows is lovely. It's a lot of fun to watch these different kinds of puzzle, and this one was just a perfect pick
After watching you solve the first puzzle I tried the second one on my own and solved it in 33 minutes which is very fast for me. It was fun! The fact that some digits themselves are clues adds a nice logic to it. I wouldn't mind if you occasionally feature Kakuro or a variant like this second puzzle on the channel.
I'm not that familiar with Kakuro, so for clarity: an "entry" refers to _any_ and every contiguous group of cells within a row or column, _even if its sum is not given_ (note how row 8 and c3r2-6 have no given sums).
I certainly don’t mind more kakuro. Particularly elegant variations such as the second puzzle! Nice to have 2 simpler puzzles too rather than some of the recent beasts, got to keep a good mix!
Before discovering this channel and all of the variants of Sudoku out there, I always considered Sudoku to be the "boring" puzzle type and therefore gravitated more towards Kakuro. But having played these two puzzles, I completely agree with Simon's assessment that a handcrafted Kakuro is much more enjoyable than the standard Kakuro you'll find in a book. Killer Sudoku has become my favorite since it's sort of a blend of Sudoku and Kakuro.
Thanks for picking up and showing the trick at the end of the first puzzle. I was about to post a grumpy comment about how the first 80% was simple and the last bit was evil!
I have done a reasonable number of kakuro puzzles before and that variant kakuro was really fun to do! would love to see other variant kakuro puzzles in the future!
I struggled a little with the logic in the first puzzle and had to keep reverting to the solution video when stuck. the second puzzle is gorgeous though. I needed some assistance getting the premise to work in my head, but once I had it, I colour-coded the grey cells to be either down or across (turns out there weren't any that did both) and managed to solve it in under 20 minutes, which for me was a massive achievement. Bravo Prasanna for the excellent puzzles.
Ok the 2nd one was actually "easier" for me, because I didn't know the geometry trick near the end of the 1st puzzle. Very neat trick. :) I love me some Kakuro! Give us more of these!
Simon - Very classy (and a great help to the rest of us) for explaining yesterdays Clover puzzle. Today's puzzle - I agree, the newspaper ones are boring, which may explain why I have never gotten interested in Kakuro puzzles. Maybe I'll have to try and find some of the good ones. These were very interesting.
Simon Anthony I would like to think you for rejuvenating my love for Sudoku. I have begin to be bored and hate expert level normal Sudoku. I will say I am starting to grow more and more into these newer puzzles. I am loving Chess Sudoku the most tho. And if you do read this awesome, but I know it will be buried in comments. Thanks for your time.
I've periodically wondered why you haven't done a Kakuro or two on this channel. Really enjoyed these - both took me ~12 minutes, and I felt like I was going at a decent rate (until the trick in the first one ground me to a halt).
little simpler near end of first puzzle: add bottom of columns 4-6: 17+13+21 = 51, then subtract 6 (16-10) and 23 (bottom row) that give sum of center 3 digits of row 7 (14). That disambiguated possibilities in center and then finish the bottom corners last.
I like these two part solves, where you claw your up the sheer cliff face, then come back and show us the elegant staircase up the mountain the next day.
Personally, I solved it by noting that I had the total of all the digits for the little 3x4 box in the lower middle; namely, 17 + 13 + 21 = 51. Then, the bottom 2 rows of that 3x4 bit sum to 31 (8 + 13), so the remainder must sum to 20. Subtract the 6 from the 3 cells at the top, and you're left with 14 in 3 cells, with the middle cell of those 3 limited to {1,2,4}. This doesn't get you the answer immediately like Simon's method did, but it does make the problem a lot more manageable, and in fact entirely solvable if you then look at the entire 9-cell row the 14 sum appears in. The main upshot of this method over Simon's method is that it is probably easier to spot.
It makes sense for those who already know how that "Check" button works. It simply does standard Sudoku logic, i.e. checking all the rows and columns (and 9-cell areas, whether 3x3 or otherwise, if they are given) and seeing if they don't contain duplicate digits. This doesn't work in a Kakuro, because multiple entries can appear in the same row or column and can then share digits between them (such as a 2 appearing in all 3 8-entries on the 2nd row of the first puzzle in this video). But, of course, it is very easy to have never come across the bit in some of their videos where they explain what the "Check" function that is underneath the eponymous button actually does.
I'm always sad when there's a clever and/or on theme bit of logic that's missed because it's found another way. In the last puzzle, the 18 clue at the bottom left was the very first thing I did, since it's the same logic as the 12 clues to give the 6. And then the teasing that he's going to get it at 33:50 where he said something like "there's two gray cells I should be looking at", with only 4 gray cells left (and one of them the 18 clue), and then goes on to explain something more complicated. I'm not judging the solve or anything, since it's very hard to not miss something, but just commenting on the feeling I get.
The problem here is that he solved the 12 clues by making the white cells as low as possible, which left the grey cells as a 6, meaning those grey cells could be neither higher nor lower. This doesn't work for the 18 clues, because the 3 white cells in the 18 clue aren't limited in the same way. My point being: I don't think Simon ever realized that if a grey cell appears as the first cell in an entry whose total is given, and is summing all the rest of that entry, that the grey cell must then be exactly half of the entry. And it is of course precisely this realization which solves the 18 clue.
Definitely like to see more of these. They used to be my strongest puzzle type (I aspired to competent) but, as I demonstrated with these, I'm a bit rusty.
Got the first one in about half an hour, which I'm pretty happy with for my first real attempt at a kakuro. I did the maths at the end a bit differently, using the 17,13,21 clues and the 8,23 clues at the bottom to work out the sum value of the 3 middle cells in row 7. Not as clean as finding the value of the empty cell in c1, but it worked out for me. :)
Kakuro was actually invented by a Canadian in 1966, who called it Cross Sums. The name "kakuro" got added decades later. I played them often in Dell Magazines' puzzle books as a kid in the 1980's and 1990's.
I didn't know it was a Canadian who created the first 'Cross Sums'. . I do remember when Sudoku puzzles were called 'Number Place', in the same magazine.
I feel like sudoku puzzles, after the Japanese got through with them, were a lot more elegant than the original number place puzzles. As I recall, It was rare for the Number Place puzzles, even the ones marked "hard", to need anything more complicated than an X-wing to solve. Often puzzles had 1/3 to 1/2 of the grid filled in to start with. Certainly the logic and theory of these puzzles has been substantially elevated since those early days. On the other hand, I don't feel like kakuro is significantly different from cross sums. As Simon said, it's rare for the game, regardless of which name you call it, to require a trick like the one seen in the first puzzle in the video. So kakuro and cross sums are essentially identical games, whereas sudoku is the "grown up" form of number place.
Got 5:25 for the first puzzle, and 12:18 for the second; the second was definitely slower as I'm so used to solving standard kakuros that it took a while to get into rhythm. Both very fun, and I miss nikoli.com, where I did really well for the kakuro solves. Just a note: the 'trick' you mention in the first puzzle was actually very common in the Nikoli harder puzzles, and I learned to minimize how many sums I needed to actually look at to narrow down possiblities (which I did with this puzzle by knowing that r7c8 and r7c9 summed to 5, then finding the sum of r4c4-r4c6 by taking the three bottom sums in c4-c6 and subtracting the two middle sums in r8 and r9 (along with the 6 of what was left in r6's sum).
@25:55 Gotta love when Simon focus's so much that he overwrites his own pencil marks, losing some easy progress. For those (like myself) that can't remember one number (131) while adding up a bunch of other numbers....you could just subtract from 131 working down: 131 - 3 - 22 - ....
37:50 that grey nine was solvable right from the start - the grey could only sum up the right side and the puzzle gives you the total of both as 18, so 2x=18 or x=9.
@@edsimnett well, its partly the definition of "normal". Normal for the channel? Perhaps, but it's clear this isn't Sudoku so there is no reason to actually assume that a rule would just repeat. Normal for puzzles as a whole, no. Normal for Kakuro, no. As a general rule when exploring puzzles, it's good to not assume things unless explicitly stated. That being said it may have been good to explain the unlabeled rows ya. I am defending Simon more (I have agreed about some rules goofs in the past) because this time, as someone who has solved kakuro already, it was really difficult to foresee the issues people would have because it's all normal Kakuro for him. Also, one key thing is to always read the description and not just watch the video because sometimes if they think a goof is big enough they do edit the description (I say that without checking if they have done so this time, just always a good idea)
It's difficult to estimate that because the actual contest had not just these two but 20 puzzles in total. I can tell you that Ken Endo topped the contest by solving all 20 in 74 minutes. These two puzzles were worth 130 points out of 1000 and I believe he solved them in about 3:30 and 4 and something minutes for the variant based on his submission times.
@@PrasannaSeshadri16 thanks for the reply! But I was refering to the video Simon talks about during the solve... someone named Jason. He said he would put a link but I didnt see one... awesome puzzle by the way!! Hope to see more kakuro variant on the channel!
That Clover Leaf puzzle may have been the one and only occasion when i had about half of the squares filled by the time of Simon having found the first digit. I even doubted myself and had to stop and triple check by watching the video first; i was like "No way i got this right... its an hour long video. i have to have messed something up."
Dell magazine has been publishing 'Cross Sums' for as long as I can remember (going back to the 80s, and likely much further); I've always called Kakuro puzzles 'Cross Sums' for this reason. (They also had 'Number Place' puzzles that we know better as Sudoku.) . I must admit, I've never seen a Kakuro that had missing clues before ... and I *certainly* have never seen a variant like that found in the second puzzle. The only variants I have seen (in the puzzle magazine mentioned above) are (1) one where each row/column needed exactly one zero, and (2) one where each row and column needed exactly one repeated digit. . All in all, I'm a big fun of Kakuro ... and I would LOVE to see more that variants have to offer!
The variant is something I came up with specifically for my contest so I am not surprised you haven't seen it before. Ones with missing clues aren't as rare though, I believe there are some on Grandmaster Puzzles along with some other variants.
I remember enjoying a few Cross Products in Dell magazines, another fun variation. Good to know that I am not the only one that knows that Dell invented these 2 puzzles. A prophet in his own land...
Took me 13:00 for the first one. I've done lots of these puzzles over the years and it was all straightforward. The end is a very easy bifurcation, no need to add up a bunch of numbers (and possibly add them up wrong). I don't have time now for the second one, although it sounds interesting!
It might be an easy bifurcation, but Simon and Mark and a lot of people watching them don't like bifurcations, and therefore they and us refuse to do them.
For a long time the 23 down is marked as 968 the 18 across has to be 9261, that fixes the 89 in the bottom row. Also the 12 across in the middle has been 6132 for a while. it also makes left column 68715239 the two gray cells on the left start 5826, fixing the 36 pairs, the 23 pairs (including the one that you didn't have yet in column 1. Pretty much everything can be filled in.
EDIT: Final times 11:05 and 9:45 ---- When you know that a grey cell at the beginning of a clue must go in the same direction as the original clue (and all grey cells in the clue go in the same direction as the clue) then you know that the sum of the grey cells must be half of the original clue (12 => 6, 18 => 9). This gives you a bit of logic to speed up the solve a bit. @27:25, once the 2 is placed in the 26 clue (and realizing that the 11 clue can no longer be 4-7), then you know that both grey cells in the 34 clue are down clues (top one across would have to be at least 10 at that point). Therefore, the sum of the two grey cells is half the total (17) which makes it an 8/9 pair, linking an entire chain of 8/9 pairs (I had solved the 18 clue previously due to the above rule). Solving the 11 clue shortly after will lead to a lot of quick entries. (2nd Edit: He realized this at 31:25)
Rather than the sum/subtraction trick, you can get there with eliminating candidates on the 8 vs 21 in (maybe roughly) the same amount of time. Knowing the 3 helps tremendously though, neat trick!
Does the 'Check' button not work for Kakuro? Got stuck at the point Simon had to do the maths. Took his hint and completed the puzzle but the checker said no! Reset it all. Did it again. Still no. But I had the same result as the video ...
No, the check button only works for standard Sudoku solutions. Unfortunately, it's been the source of confusion for newcomers to the channel for as long as I've been subscribed (6 months). They occasionally mention it won't work for certain puzzles, but unless you've seen one of the videos they mention it, you're out of luck.
The CTC web app only checks classic Sudoku constraints so it can't check this puzzle. If your solution matches Simon's that should be enough to know it's right :)
I really enjoyed the second puzzle. The first one I didnt like nearly as much because I didnt catch the arithmetic trick at the end and had to just bifurcate. The second one though felt very nice, and I definitely got the sense of learning the trick from the 12s. That said, I made a mistake at the end so I had to watch most of the video before realizing that the 8 clue could be 6-2 instead of just 3-5. Got most of it though.
Thanks for covering these puzzles :)
If anyone wants to access the puzzle booklet that is linked to in the description to check out the other puzzles of the contest, the password is pUZZLEsQUARED^2
We'll upload a password-less booklet by tomorrow mostly.
thanks. There are some really nice ones
Excellent puzzle! 🧩
Thank you for the added puzzles, too bad I can't open it on my android phone, beacuse the plugin is not supported anymore (or did i somehow block the plugin?)
@@DavidHsueh you don't need the plugin to see and download the puzzle booklet. Otherwise if you want to participate in future contests you do need flash for now.
@@PrasannaSeshadri16 I'm so dumb, didn't interpreted the booklet as a download, but as a password protected 'game' run in a plugin. And i see it has already been undone from its password. Thank you again
Kakuro is one of my favorite puzzles and I would love to see more.
38:03 had me laughing out loud! Instead of using the total of the 35 clue, Simon calculates the 2 digits that must be missing from the row...Of course it doesn't matter much, you get to the same digit, but still hilarious :D
Brilliant puzzle though! What a fantastic idea to use those grey cells as kakuro clues
Thank you :) the whole contest was themed on variants of puzzles where the puzzle rule itself doubled up into them somehow. Check it out, link in the description.
I just added a comment with the password too.
@@PrasannaSeshadri16 Definitely going to check it out, although I fear they are way beyond my skills! I love watching both Mark and Simon solve these, and I can pretend to be a bit faster on some digits, although they both solve half of the grid when I am still shouting at the screen :D
@@11mandylion come join our discord group if you haven't yet, try the welcome pack there and join in the discussions, you will quickly become better :)
It's actually faster to do it this way (if you don't have to explain what you are doing...)
So, the solution to the cloverleaf puzzle was like finding a four-leaf clover, tearing each leaf and making a wish. You gotta work on each leaf in order. Beautiful!
The intended solution for the clover kind of explains why it was a tribute to ahaupt. It's similar to the trick they used in the infamous "Expert Puzzler Gets Pranked" puzzle.
Finally! I feel in love with kakuros this summer and am so happy you started taking on them! Even the "dull" ones seemed fun!
I love Kakuro puzzles. Probably my favourite puzzle type of all. Thanks for the video showcase of some absolute beauties!
Really appreciate you going back to yesterday's puzzle. Thought your approach wasn't quite right at the time (not that I could do any better!), so really like that you took a moment to show the true elegance of the puzzle.
Haven't done Kakuro for quite some time. I used to do them in puzzle books and always loved them. These were especially fantastic editions of the style. Keep them coming Simon!
08:35 for the first one, and 14:42 for the second one! Please feature more Kakuros!
concur, were fun
I agree. Kakuros are my favorite!
I am addicted to both Killer Sudoku and Kakuro puzzles so was thrilled to see today's offering. More please.
This was my first crack at these kinds of puzzles (and I don't do a ton of killer sudoku)...Puzzle 1 didn't take me too long but naturally I got stuck on the bottom middle section - never occurred to me to do macro-arithmatic to solve it
Edit: I almost chickened out of Puzzle 2...But, I decided, what the heck, I'll give it a shot, and I managed to solve it! Official time was over 3 hours, but I got there eventually. That was fun!
Both puzzles were an absolute joy to solve! I nearly made some mistakes here and there, but managed to crack both of them in just under 30 minutes apiece. I especially liked the second puzzle - the gray cells were used in a very clever way in a puzzle that was otherwise fairly low on clues.
I would love to see more Kakuro in the future!
Also, thank you for bringing Kakuro! It's the first time I played this kind of puzzle, I really liked it! And props to your solutions, specially the second one, it was amazing how quickly you spoted all that the creator probably intended (it took me a while to get everything, but I'm happy not needing to bifurcate as in the first one).
38:08 shows us a window into simon's mind. instead of just doing the sum of the row to find the 2, he went on a very different way of finding the 2(by using 1...9 sums up to 45, etc)
When you are experienced at solving these, Simon's way is actually a much faster way to do it.
It's a standard Kakuro technique.
Love to see you covering Kakuro. I've always struggled with the ones I've tried yet you make them seem so straight forward.
Great solve! Normally not a fan of kakuro so happy to leave it there for kakuro puzzles, but open to interesting kakuros!
This was my first time seeing a Kakuro puzzle so I just watched. Very interesting.
My way to start the Phistomefel puzzle is simpler and doesn't use a system of equations. Look at the bottom 4 rows instead of the top. Subtract the bottom right box and all the cages. We see the remaining 8 cells sum to 20 and they come in two groups of 4, so they must be two lots of 1234.
13 minutes for the second one. 13 minutes of pure enjoyment. Thank you.
Thanks for covering a kakuro puzzle! Love these puzzles and glad to see one on the channel 😊
28:37 for the first puzzle and 33:08 for the second puzzle. This is my first time to solved kakuro puzzle and it's very beautiful and very enjoyable puzzle! Brilliant!
This was a great contest! I hope other puzzles in this contest are covered as well.
ovotovatatavotovo?
@@bakpaopuz For sure
For those who are reading this and haven't seen the contest PDF that is actually one of the puzzle names and not just bak going into gibberish fanboy mode over the contest :p
@@PrasannaSeshadri16 Thank you for clarifying
This second puzzle is so great! The logic it follows is lovely. It's a lot of fun to watch these different kinds of puzzle, and this one was just a perfect pick
I am in awe of your solving of the second puzzle! Bravo!
I solved the 1st one without the video! It was so much fun! Took me a little over an hour, but it was time well spent!
After watching you solve the first puzzle I tried the second one on my own and solved it in 33 minutes which is very fast for me. It was fun! The fact that some digits themselves are clues adds a nice logic to it.
I wouldn't mind if you occasionally feature Kakuro or a variant like this second puzzle on the channel.
Kakuro have always been my favorite puzzles so I really enjoyed this!
I absolutely love kakuro!!!! I want moooooore, these two puzzles were too easy
I'm not that familiar with Kakuro, so for clarity: an "entry" refers to _any_ and every contiguous group of cells within a row or column, _even if its sum is not given_ (note how row 8 and c3r2-6 have no given sums).
I certainly don’t mind more kakuro. Particularly elegant variations such as the second puzzle!
Nice to have 2 simpler puzzles too rather than some of the recent beasts, got to keep a good mix!
Before discovering this channel and all of the variants of Sudoku out there, I always considered Sudoku to be the "boring" puzzle type and therefore gravitated more towards Kakuro. But having played these two puzzles, I completely agree with Simon's assessment that a handcrafted Kakuro is much more enjoyable than the standard Kakuro you'll find in a book.
Killer Sudoku has become my favorite since it's sort of a blend of Sudoku and Kakuro.
Yes, Love Kakuro! More please!
Thanks for picking up and showing the trick at the end of the first puzzle. I was about to post a grumpy comment about how the first 80% was simple and the last bit was evil!
I have done a reasonable number of kakuro puzzles before and that variant kakuro was really fun to do! would love to see other variant kakuro puzzles in the future!
I've done thousands of large, hard kakuro puzzles but probably never a hand crafted one. These were great fun! Please include more kakuro on CtC
Indeed, have always thought Kakuro puzzles were spectacularly tedious, but these were great, particularly the second one.
I've never seen kakuro but I love it. More please
Glad you went over cloverleaf again. I knew it couldn’t have been that rough a start for such a beautiful puzzle
Love Kakuro so much, please do more! 😁
Really great puzzles, I didn't know Kakuro until now!
I struggled a little with the logic in the first puzzle and had to keep reverting to the solution video when stuck. the second puzzle is gorgeous though. I needed some assistance getting the premise to work in my head, but once I had it, I colour-coded the grey cells to be either down or across (turns out there weren't any that did both) and managed to solve it in under 20 minutes, which for me was a massive achievement. Bravo Prasanna for the excellent puzzles.
I would love to see it occasionally! Thank you for sharing it with us
These were great kakuro puzzles. Quite tricky, but not nearly as brain-melting as I expected.
Very nice, I'd love to see some more of these, please.
Ok the 2nd one was actually "easier" for me, because I didn't know the geometry trick near the end of the 1st puzzle. Very neat trick. :)
I love me some Kakuro! Give us more of these!
Simon - Very classy (and a great help to the rest of us) for explaining yesterdays Clover puzzle.
Today's puzzle - I agree, the newspaper ones are boring, which may explain why I have never gotten interested in Kakuro puzzles. Maybe I'll have to try and find some of the good ones. These were very interesting.
Been waiting for a kakuro puzzle!
Yay! I love kakuro, and these were magnificent, of course.
More of these please!
LOVE this! Kakuros are great
First time I've done a kakuro variant and I loved it.
Simon Anthony I would like to think you for rejuvenating my love for Sudoku. I have begin to be bored and hate expert level normal Sudoku. I will say I am starting to grow more and more into these newer puzzles. I am loving Chess Sudoku the most tho. And if you do read this awesome, but I know it will be buried in comments. Thanks for your time.
Amazing video, always wondered how to do these.
Please somebody help. Why is the R4C6 clue a 2 at 27:25 given that the gray 3 clue is already satisfied?
The grey 3 clue isn't satisfied by the across digits, since they sum to 9 (=1+2+6). So has to be satisfied by the down digits.
I've periodically wondered why you haven't done a Kakuro or two on this channel. Really enjoyed these - both took me ~12 minutes, and I felt like I was going at a decent rate (until the trick in the first one ground me to a halt).
34:47
Using the grey square at the bottom of the left hand column forces the grey square in the bottom row.
little simpler near end of first puzzle: add bottom of columns 4-6: 17+13+21 = 51, then subtract 6 (16-10) and 23 (bottom row) that give sum of center 3 digits of row 7 (14). That disambiguated possibilities in center and then finish the bottom corners last.
Great video great puzzle was very fun about 25 mins for the 2nd puzzle
I like these two part solves, where you claw your up the sheer cliff face, then come back and show us the elegant staircase up the mountain the next day.
I got stuck on the "trick" in puzzle 1 for quite a while. not sure I would ever have spotted it without the video. very sneaky.
Personally, I solved it by noting that I had the total of all the digits for the little 3x4 box in the lower middle; namely, 17 + 13 + 21 = 51. Then, the bottom 2 rows of that 3x4 bit sum to 31 (8 + 13), so the remainder must sum to 20. Subtract the 6 from the 3 cells at the top, and you're left with 14 in 3 cells, with the middle cell of those 3 limited to {1,2,4}.
This doesn't get you the answer immediately like Simon's method did, but it does make the problem a lot more manageable, and in fact entirely solvable if you then look at the entire 9-cell row the 14 sum appears in.
The main upshot of this method over Simon's method is that it is probably easier to spot.
39:10 Simon - The check function won't work
Me - After doing the first puzzle twice and comparing my solution to Simon's - "Now he tells me!"
It makes sense for those who already know how that "Check" button works. It simply does standard Sudoku logic, i.e. checking all the rows and columns (and 9-cell areas, whether 3x3 or otherwise, if they are given) and seeing if they don't contain duplicate digits.
This doesn't work in a Kakuro, because multiple entries can appear in the same row or column and can then share digits between them (such as a 2 appearing in all 3 8-entries on the 2nd row of the first puzzle in this video).
But, of course, it is very easy to have never come across the bit in some of their videos where they explain what the "Check" function that is underneath the eponymous button actually does.
Ah! That explains it then! So, first one solved in about 22mins... right, now puzzle 2!
Loved those puzzles!
I really liked that 34=2x+2y clue, clever stuff.
I'm always sad when there's a clever and/or on theme bit of logic that's missed because it's found another way. In the last puzzle, the 18 clue at the bottom left was the very first thing I did, since it's the same logic as the 12 clues to give the 6. And then the teasing that he's going to get it at 33:50 where he said something like "there's two gray cells I should be looking at", with only 4 gray cells left (and one of them the 18 clue), and then goes on to explain something more complicated. I'm not judging the solve or anything, since it's very hard to not miss something, but just commenting on the feeling I get.
lol It was literally the first thing I spotted too, and then he went on, and on, and on...
The problem here is that he solved the 12 clues by making the white cells as low as possible, which left the grey cells as a 6, meaning those grey cells could be neither higher nor lower. This doesn't work for the 18 clues, because the 3 white cells in the 18 clue aren't limited in the same way.
My point being: I don't think Simon ever realized that if a grey cell appears as the first cell in an entry whose total is given, and is summing all the rest of that entry, that the grey cell must then be exactly half of the entry.
And it is of course precisely this realization which solves the 18 clue.
Definitely like to see more of these. They used to be my strongest puzzle type (I aspired to competent) but, as I demonstrated with these, I'm a bit rusty.
Got the first one in about half an hour, which I'm pretty happy with for my first real attempt at a kakuro. I did the maths at the end a bit differently, using the 17,13,21 clues and the 8,23 clues at the bottom to work out the sum value of the 3 middle cells in row 7. Not as clean as finding the value of the empty cell in c1, but it worked out for me. :)
Kakuro was actually invented by a Canadian in 1966, who called it Cross Sums. The name "kakuro" got added decades later. I played them often in Dell Magazines' puzzle books as a kid in the 1980's and 1990's.
I didn't know it was a Canadian who created the first 'Cross Sums'.
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I do remember when Sudoku puzzles were called 'Number Place', in the same magazine.
I feel like sudoku puzzles, after the Japanese got through with them, were a lot more elegant than the original number place puzzles. As I recall, It was rare for the Number Place puzzles, even the ones marked "hard", to need anything more complicated than an X-wing to solve. Often puzzles had 1/3 to 1/2 of the grid filled in to start with. Certainly the logic and theory of these puzzles has been substantially elevated since those early days.
On the other hand, I don't feel like kakuro is significantly different from cross sums. As Simon said, it's rare for the game, regardless of which name you call it, to require a trick like the one seen in the first puzzle in the video. So kakuro and cross sums are essentially identical games, whereas sudoku is the "grown up" form of number place.
Is anyone having trouble with the website saying that you’re wrong when you aren’t?
The logic to get the grey cells coming down from 34 in the second puzzle is particularly nice
Nice usage of grey cells, Simon!
Got 5:25 for the first puzzle, and 12:18 for the second; the second was definitely slower as I'm so used to solving standard kakuros that it took a while to get into rhythm. Both very fun, and I miss nikoli.com, where I did really well for the kakuro solves. Just a note: the 'trick' you mention in the first puzzle was actually very common in the Nikoli harder puzzles, and I learned to minimize how many sums I needed to actually look at to narrow down possiblities (which I did with this puzzle by knowing that r7c8 and r7c9 summed to 5, then finding the sum of r4c4-r4c6 by taking the three bottom sums in c4-c6 and subtracting the two middle sums in r8 and r9 (along with the 6 of what was left in r6's sum).
@25:55 Gotta love when Simon focus's so much that he overwrites his own pencil marks, losing some easy progress.
For those (like myself) that can't remember one number (131) while adding up a bunch of other numbers....you could just subtract from 131 working down:
131 - 3 - 22 - ....
37:50 that grey nine was solvable right from the start - the grey could only sum up the right side and the puzzle gives you the total of both as 18, so 2x=18 or x=9.
More of kakuro please!
In the first puzzle, how do we know that the two unlabelled rows are considered to be entries?
I see entry as just an uninterrupted horizontal or vertical line of white cells.
@@edsimnett well, its partly the definition of "normal". Normal for the channel? Perhaps, but it's clear this isn't Sudoku so there is no reason to actually assume that a rule would just repeat. Normal for puzzles as a whole, no. Normal for Kakuro, no. As a general rule when exploring puzzles, it's good to not assume things unless explicitly stated.
That being said it may have been good to explain the unlabeled rows ya. I am defending Simon more (I have agreed about some rules goofs in the past) because this time, as someone who has solved kakuro already, it was really difficult to foresee the issues people would have because it's all normal Kakuro for him.
Also, one key thing is to always read the description and not just watch the video because sometimes if they think a goof is big enough they do edit the description (I say that without checking if they have done so this time, just always a good idea)
33:42 "I must be looking for another gray cell, I think" … I think Simon has quite a lot of gray cells already.
Great puzzles I would like to see more
Nice to see kakuro on here! :)
Where is the link to the video of the fastest solver!? I want to see that
It's difficult to estimate that because the actual contest had not just these two but 20 puzzles in total. I can tell you that Ken Endo topped the contest by solving all 20 in 74 minutes. These two puzzles were worth 130 points out of 1000 and I believe he solved them in about 3:30 and 4 and something minutes for the variant based on his submission times.
@@PrasannaSeshadri16 thanks for the reply! But I was refering to the video Simon talks about during the solve... someone named Jason. He said he would put a link but I didnt see one... awesome puzzle by the way!! Hope to see more kakuro variant on the channel!
31:25 This is easily my favorite moment of this video - just so brilliant and elegant!
Being forced to use our brains 😊
That Clover Leaf puzzle may have been the one and only occasion when i had about half of the squares filled by the time of Simon having found the first digit. I even doubted myself and had to stop and triple check by watching the video first; i was like "No way i got this right... its an hour long video. i have to have messed something up."
The puzzle check doesn't work on Kakuro.
Dell magazine has been publishing 'Cross Sums' for as long as I can remember (going back to the 80s, and likely much further); I've always called Kakuro puzzles 'Cross Sums' for this reason. (They also had 'Number Place' puzzles that we know better as Sudoku.)
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I must admit, I've never seen a Kakuro that had missing clues before ... and I *certainly* have never seen a variant like that found in the second puzzle. The only variants I have seen (in the puzzle magazine mentioned above) are (1) one where each row/column needed exactly one zero, and (2) one where each row and column needed exactly one repeated digit.
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All in all, I'm a big fun of Kakuro ... and I would LOVE to see more that variants have to offer!
The variant is something I came up with specifically for my contest so I am not surprised you haven't seen it before. Ones with missing clues aren't as rare though, I believe there are some on Grandmaster Puzzles along with some other variants.
I remember enjoying a few Cross Products in Dell magazines, another fun variation. Good to know that I am not the only one that knows that Dell invented these 2 puzzles. A prophet in his own land...
YES, More non sudoku puzzles!
Took me 13:00 for the first one. I've done lots of these puzzles over the years and it was all straightforward. The end is a very easy bifurcation, no need to add up a bunch of numbers (and possibly add them up wrong). I don't have time now for the second one, although it sounds interesting!
It might be an easy bifurcation, but Simon and Mark and a lot of people watching them don't like bifurcations, and therefore they and us refuse to do them.
For a long time the 23 down is marked as 968 the 18 across has to be 9261, that fixes the 89 in the bottom row. Also the 12 across in the middle has been 6132 for a while. it also makes left column 68715239 the two gray cells on the left start 5826, fixing the 36 pairs, the 23 pairs (including the one that you didn't have yet in column 1. Pretty much everything can be filled in.
EDIT: Final times 11:05 and 9:45
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When you know that a grey cell at the beginning of a clue must go in the same direction as the original clue (and all grey cells in the clue go in the same direction as the clue) then you know that the sum of the grey cells must be half of the original clue (12 => 6, 18 => 9). This gives you a bit of logic to speed up the solve a bit.
@27:25, once the 2 is placed in the 26 clue (and realizing that the 11 clue can no longer be 4-7), then you know that both grey cells in the 34 clue are down clues (top one across would have to be at least 10 at that point). Therefore, the sum of the two grey cells is half the total (17) which makes it an 8/9 pair, linking an entire chain of 8/9 pairs (I had solved the 18 clue previously due to the above rule). Solving the 11 clue shortly after will lead to a lot of quick entries. (2nd Edit: He realized this at 31:25)
Would love more kakuro
Rather than the sum/subtraction trick, you can get there with eliminating candidates on the 8 vs 21 in (maybe roughly) the same amount of time. Knowing the 3 helps tremendously though, neat trick!
Missing a couple of row/column totals in the first puzzle? I've never seen that before.
I assume Kokura allows numbers to repeat in rows/columns? (This was my first kokuro)
They can repeat in rows and columns just not within a continuous line of white cells.
Does the 'Check' button not work for Kakuro? Got stuck at the point Simon had to do the maths. Took his hint and completed the puzzle but the checker said no! Reset it all. Did it again. Still no. But I had the same result as the video ...
No, the check button only works for standard Sudoku solutions.
Unfortunately, it's been the source of confusion for newcomers to the channel for as long as I've been subscribed (6 months). They occasionally mention it won't work for certain puzzles, but unless you've seen one of the videos they mention it, you're out of luck.
@@RichSmith77 Yeah, thanks. He actually mentioned it on the second puzzle once I'd watched that far.
I solved the first kakuro correctly but it says wrong. Could you fix that? It’s the same as yours.
The CTC web app only checks classic Sudoku constraints so it can't check this puzzle. If your solution matches Simon's that should be enough to know it's right :)
@@PrasannaSeshadri16 Ok thats good to know. Thanks. Nice puzzle btw.
@@greefkarga7898 thank you :)
ahhh i’ve been waiting for kakuro!
I got about as far as 15:40, almost exactly the same, but couldn't see how to proceed from there.
THIS PUZZLE WAS FUN!
Thank you for revisiting yesterday's puzzle. There is no shame in seeing things differently! Why would we want everyone to see the 'intended' way in?
I really enjoyed the second puzzle. The first one I didnt like nearly as much because I didnt catch the arithmetic trick at the end and had to just bifurcate. The second one though felt very nice, and I definitely got the sense of learning the trick from the 12s. That said, I made a mistake at the end so I had to watch most of the video before realizing that the 8 clue could be 6-2 instead of just 3-5. Got most of it though.
Can we use our Sudoku Bingo cards on Kakuro puzzles?
Long time ago I haven't done Kakuro
The first one in 26 min
The second one in 34 min
FYI: The solution of the first given at 19:40
Thanks Prasanna