Need help learning advanced kakuro strategies (Full Version)

 Message

 Fonze -> Need help learning advanced kakuro strategies (10/10/2020 2:21:58 AM) Hello all. I've recently joined this forum hoping to connect with others who enjoy kakuro puzzles as I do. Unfortunately the amount of us seems to be fairly small and thus I don't have many outlets to turn to when looking to expand my knowledge and skill repertoire when doing these puzzles. I'm well-versed in many skills needed to do these, up to and including taking the difference of rows and columns to find the values or relationships between (groups of) squares, but I still find myself struggling on some puzzles, so I know there is more for me to learn. Unfortunately most online posts and blogs I've seen offer only a select few bits of insight beyond the rudimentary level solving techniques and the rest are research papers on programming a solver, which is a bit beyond my current understanding, as I am not very familiar with coding and the logic that goes into that; thus this post. Context aside, here are some puzzles that show where my skill level stops: [Image]https://i.imgur.com/IwUeRkY.jpg[/image] This first one I think is a good example for how small the unsolved portion is; while it is trivial to guess-and-check the solution I struggle to find the logical way to deduce the correct solution without guessing. I've gone as far as to figure out the relationships between each of the 4 major "groupings" here but nailing down their values proves to be out of my current understanding, or maybe this bit of information is unrelated/unresolvable: [image]https://i.imgur.com/OhQWdC9.jpg[/image] A lot of information can be gleaned from this, however this is also one of the many cases where this information at the least needs to be teamed up with something else. I cant see a way to cross-reference any of these pieces together to get the solution, which is apparently that x=18 and y=14. Again, even this info may not solve the puzzle, which is the real goal here, and this info could be totally irrelevant in my lack of understanding of finding the next actual step. [Image]https://i.imgur.com/k0c3WVM.jpg[/image] This second one is a good example because it is such a common shape for being very difficult, in large part due to the fact that one can only cleanly cut the puzzle to find the difference between columns and rows two ways, due to the diagonal sections running through the center between sides. Also, it only leaves sections of 3 for that, so one really cannot compare one single square against anything else. I hope somebody here will see this and help me further my learning of these amazing puzzles; thanks in advance and happy puzzling :)

 kimbro84 -> RE: Need help learning advanced kakuro strategies (10/12/2020 8:41:47 AM) Your work is awesome! I found a couple tricks that worked, these are probably basic but you never know! I've learned any connecting squares can't have repeating number So if I have 4 squares 7 9 789 7 9 7 9 Then the top right corner HAS to be an 8. No matter if the squares are touching or are at opposite corners. So long as they have touching connectors, there can't be repeats. Another example: 7 9 789 7 9 789 The 2nd column will have to have an 8. I have found this useful for helping with removing possibilities from other cells. Another thing I found out the hard way was making groups of 7 between 32 and 40 simpler. Groups of 8 are pretty cut and dry as is the 41,42 in 7, but the groups of 7 between 32-40 were really challenging me. Here's an example, let's use 39: 45-39 = 6. So there are 2 missing squares (because it only has 7 cells). The two missing squares, if there, would bring our total to 45. They have to equal six (45-39). So one of these groups below will NOT be found in the answer: 5,1 4,2. The answer must contain 9,8,7,6,3 and then 5,1 OR 4,2. Here's an example for 34: 45-34=11. So the two 'missing squares' have to total 11. I'll have to have 9,2 8,3 7,4 6,5 Answer will be ONLY three of these groupings and a '1'. This really helps me when I have cell clues that are high and low because you can only have three high and three low. I've tried using this with groups of 5,6 but there were simply so many options once you are talking about 3 missing digits for most of the super hard puzzles. They throw in 25 in 5 and 32 in 6 and it's just too many options! The other helpful things I learned: 17 in 5 always has a 321 18 in 5 always has a 21 19 in 5 always has a 1 20 in 5 doesn't have to have a 1. 6,5,4,3,2 21 in 5 has to have at least one cell with a 7+. a 16 in three has to have at least a 7+, a 19 has to have at least an 8+ a 25 in 6 has to have a 2 and a 1, a 26 in 6 has to have a 1, a 27 is the first in 6 that doesn't have to contain a 1 (7,6,5,4,3,2) You prob know these easier ones 30 in 7 has a 5,4,3,2,1 then either a 9,6 or 8,7. Then 31 in 7 has the 4,3,2,1 and then either 9,7,5 or 8,7,6. I do the big puzzle book so these smaller combinations are not something I'm used to. Sorry I don't have any guidance on the ones you posted. I'd love to hear some of your strategies. I see a lot of your grouping and relationships have all been tested out. YOu're definitely a step ahead of me! I'm disappointed there aren't more difficult/expert tips out there. Would sure love it! Keep up the good work.

 kimbro84 -> RE: Need help learning advanced kakuro strategies (10/12/2020 8:11:52 PM) No advice on your specific puzzles. But it wasn't for lack of effort! I printed them out and tried everything I could think of with boxing and adding etc but man...those small puzzles don't give much! Here's an example of the bigger puzzle book I'm on. I applaud you for not having to write things down. My columns of the book are usually filled with random notes, I can't do the app puzzles without a notepad handy lol. So I guess we all have our own strength. I did compare the big and small and the smaller puzzles use much more of the boxing/adding/subtracting than the bigger puzzles. Which is probably why I'm terrible at that strategy. If you want a different type of challenge the conceptis books on Amazon are all really good, the book in the pic is definitely the most challenging I've ever done. I also bought Kakuro U and it's another level of difficulty, kind of like the ones you posted but larger size.

 kimbro84 -> RE: Need help learning advanced kakuro strategies (10/12/2020 8:18:57 PM) One of my favorites, but most challenging [image]local://461097/E9C6E084D9F7403DA6CC0A3042D4B29F.jpg[/image]

 kimbro84 -> RE: Need help learning advanced kakuro strategies (10/12/2020 8:30:45 PM) Here is just an image in case you were curious about the larger puzzles. Can you explain more how you use the x and y and some of your strategies?

 kimbro84 -> RE: Need help learning advanced kakuro strategies (10/13/2020 3:43:44 AM) I know this is silly but how did you get the '8' in the very first part?

 Fonze -> RE: Need help learning advanced kakuro strategies (10/13/2020 5:15:39 AM) No it's not silly at all. Apologies if the weird way I highlighted stuff here made things less clear; on other screenies I've shared in like write ups I'll usually use a different color to show the rows vs columns so it's more clear what boxes are actually being compared to what, and which set of numbers (top and right here vs bottom and left from the other perspective) are being used. I'm assuming you mean the 8 from the A-8=B with this: short answer adding/subtracting rows/columns. Long answer if you add the 3 relevant rows in the top: (41-6)+9+12=56 and subtract from that the 3 relevant columns on the right: 10+(43-3)+14=64 -> 56(rows)-64(columns)=8 in favor of the columns, thus making the 4 bottom unknown squares of the rightmost 43-column (so not counting the known 3) 8 higher than the 2 unknown leftmost squares of the top 41-row. I'm not too well versed on the names for the different techniques and of course some have multiple names, but isn't this boxing?

 kimbro84 -> RE: Need help learning advanced kakuro strategies (10/13/2020 7:16:06 AM) Yep! It all makes much more sense now. Thanks! And that sounds like a good term for it too. I'm going to start doing the smaller puzzles, thanks for the motivation. P.S. If you come upon any more strategies would love to see a post! Happy Kakuro-ing!

 Ahlyis -> RE: Need help learning advanced kakuro strategies (1/8/2021 9:56:56 PM) quote:ORIGINAL: kimbro84 I've learned any connecting squares can't have repeating number So if I have 4 squares 7 9 789 7 9 7 9 Then the top right corner HAS to be an 8. No matter if the squares are touching or are at opposite corners. So long as they have touching connectors, there can't be repeats. This is faulty logic. This makes the assumption that the puzzle has a unique solution. I NEVER use this when solving a puzzle. I always look for numbers which I can prove must be correct through pure logic instead of assumptions about how well the puzzle is formed. You are of course free to solve these however you want to. But I feel strongly that this particular "trick" is not a valid method for solving puzzles. This includes Kakuro and others where similar logic could be used. Any puzzle where I can see a section that I "know" will be a certain way because otherwise it would have multiple solutions will remain unsolved until I can find logic that PROVES the puzzle has a unique solution.

 Page: [1]