MJOYPosted: Wed Dec 7 2016 05:14 pm

Not a tech probelm, but just wondering if people solved the June 28 2016 problem completely by logic or was it necessary to guess?  I keep trying over and over, and keep getting the same stuck board where I can't eliminate any more candidates. I notice some people solved it, so it must be possible, but I can't figure out where I'm going wrong.  Thanks for any feedback.

ZyntaxPosted: Wed Dec 7 2016 09:51 pm

I just solved it. Didn't solve it when it came out.


It's logic about 1/3 of the way through then I had to make a couple of guesses and go with it. Took me about 5 min to solve it.

The nice fishPosted: Thu Dec 8 2016 03:28 pm

I re-did it without having to guess, but there were some tricky moves. A lot of the squares came from being the only possible place were a necessary number could go. But the most difficult part was probably realizing that the square at 3 down, 7 left (the upper most one in the 10-column) could not be a 1, after that a lot more numbers fell out.

MJOYPosted: Fri Dec 9 2016 06:10 pm

Thanks to the two people who responded!

To the Nice Fish:  I used logic to get it to the point where there were so few "candidates" left that I could solve it in a few more seconds by guessing, but I'd still like to know how you did it purely with logic.I didn't have a 1 in the space you mentioned. I had 356 there.  I had 12 in the square beside it, and I just had to decide between the 1 and the 2 to solve the puzzle (it was 2); however, I had to try both out with the surrounding few squares, and I consider that "guessing". No matter how much I study the board, I can't see how to complete with pure logic, so I am really impressed that you did it.

The nice fishPosted: Sat Dec 10 2016 02:49 am

I'd love to tell you how I did it, but it's difficult without knowing exactly what the board looked liked when you got stuck and had to guess. Maybe you could post an image?

MJOYPosted: Sat Dec 10 2016 06:03 pm

Hi The Nice Fish,

I scanned it and tried to post the image but I couldn't figure out how to do it as a file. (It seemed to require a link, and I don't have a website right now that i could put it on.)  Now we're on a whole new support topic. How do you post an image that has been scanned as a file? Moderator?

The nice fishPosted: Sun Dec 11 2016 05:18 am

You could, for example, use to upload the image, and then post the link. That would probably be easiest.

MJOYPosted: Sun Dec 11 2016 11:20 pm

Thanks for the suggestion! Here's the URL--see if it works.

The nice fishPosted: Tue Dec 13 2016 11:32 am

Your link works great :) Maybe I got lucky when I first solved it after your post, but I can't seem to be able to do it that easily again. I probably made a mistake that turned out to be correct.

Anyway, it is still possible to solve with logic, using the fact that the sum of these columns are 29, while these rows are 21. So the three squares not overlapping must have the sum 29-21=8, which is impossible using the 6. So that cell becomes a 3, and after that the rest falls out.

I do however realize that it is probably a lot faster to guess than finding this trick, but I think it's much more enjoyable being able to solve them without guessing :)

Last Edited: Tue Dec 13 2016 11:35 am
MJOYPosted: Wed Dec 14 2016 11:55 am

Thank you so much for taking the time to share this with me. I loved your "logic" solution--I would never have thought of that strategy myself, and it was good for my elderly brain to study it until I understood it. I will try it out next time I have another deadlock on a hard practice puzzle and don't want to guess..  Also, thanks for telling me about Imgur--I once tried "Dropbox" but didn't like it; I  found Imgur easier to deal with, and it will come in handy.

The nice fishPosted: Wed Dec 14 2016 12:22 pm

Glad I could help :)