10 votes

Solving a Sudoku whose only clue is a single line

8 comments

  1. [4]
    cfabbro
    (edited )
    Link
    I recently starting watching Cracking the Cryptic again after taking a long break away from it, and this one in particular really blew my mind, so I thought I would share it. It's a looooooooong...

    I recently starting watching Cracking the Cryptic again after taking a long break away from it, and this one in particular really blew my mind, so I thought I would share it. It's a looooooooong video, but the puzzle is incredibly clever, and the solution is super satisfying, IMO.

    p.s. The video doesn't really start until 1:40s for those who want to get right to the "action". ;)

    3 votes
    1. [3]
      vili
      Link Parent
      I've been totally hooked on their videos these past couple of months. I would never have thought that I would enjoying watching videos of someone solving a sudoku, let alone ones that can run for...

      I've been totally hooked on their videos these past couple of months. I would never have thought that I would enjoying watching videos of someone solving a sudoku, let alone ones that can run for over two hours, but I suppose it's been a very safe and comforting escape from what has been a particularly stressful first half of the year.

      And the videos are definitely also really well made. Simon's solving style and speed in particular works really well for me, allowing me to play and think along, so to speak. Mark is sometimes just a little too fast with his deductions, so I don't feel quite as involved when watching his videos. Still, both have wonderful humour and are a pleasure to listen to.

      I actually ended up buying their book as well and have been working my way through it this summer. It's an amazing collection of brilliantly varied and inventive sudokus. I can't say that I can solve all of them on a first (or even second) try, but I can certainly say that I would highly recommend the book to anyone who loves puzzles. I've actually never cared that much for sudoku, but these puzzles are so much more than just your basic sudoku rules. Just like the videos.

      1 vote
      1. [2]
        cfabbro
        Link Parent
        Yeah, I also prefer Simon for similar reasons as you do, but also because I find his voice incredibly relaxing too. I never bought their book, but I have bought several of their iOS apps. They're...

        Yeah, I also prefer Simon for similar reasons as you do, but also because I find his voice incredibly relaxing too. I never bought their book, but I have bought several of their iOS apps. They're really good, and I would also highly recommend them to anyone who enjoys solving Sudoku puzzles.

        1. vili
          Link Parent
          I agree, Simon's voice is really relaxing. I might check out the mobile apps, although one reason I got into sudoku this summer was specifically to get away from screens. I do the puzzles on pen...

          I agree, Simon's voice is really relaxing. I might check out the mobile apps, although one reason I got into sudoku this summer was specifically to get away from screens. I do the puzzles on pen and paper.

          But then again, I have also been addictively watching Simon solve puzzles on YouTube, so I'm not sure how much my screen time has really decreased.

          1 vote
  2. [3]
    vili
    Link
    I must say that the wording for this puzzle confused me quite a bit. The way I read it, the rules seem to define a "region" as a "3x3 square", so when it later says that "each time the line passes...

    I must say that the wording for this puzzle confused me quite a bit. The way I read it, the rules seem to define a "region" as a "3x3 square", so when it later says that "each time the line passes through a region", I deducted that the parts in the bottom left where the line starts and ends cannot qualify, since the lines don't pass through the region, they start or end there. This made it impossible for me to do the initial deduction needed to start defining the regions. It's the first Cracking the Cryptic video that I have seen where I thought the instructions were unclear. But it's probably just me.

    And in all honestly, I wouldn't have been able to solve this puzzle even if I had been able to get that far! Whenever I need to start thinking about the different flavours or colours of doubles or quadruples, it all starts to go over my head, and I lose track of it on pen and paper.

    2 votes
    1. 0d_billie
      Link Parent
      I tend to find Simon is good at explaining the rules in a fairly comprehensible way, although occasionally the extra rules are so complex that it defies all understanding whatsoever. More and more...

      It's the first Cracking the Cryptic video that I have seen where I thought the instructions were unclear.

      I tend to find Simon is good at explaining the rules in a fairly comprehensible way, although occasionally the extra rules are so complex that it defies all understanding whatsoever. More and more with CtC I am just along for the ride of watching them solve the puzzle!

      3 votes
    2. vektor
      (edited )
      Link Parent
      I'm similarly unclear about the exact definition about the sum, now that I watch the video up to the point where I am in the puzzle. I was operating under the rules that: "For each region, there...

      I'm similarly unclear about the exact definition about the sum, now that I watch the video up to the point where I am in the puzzle. I was operating under the rules that: "For each region, there exists a number X, s.t. for every streak of the line through the region, digits along the streak sum to X", when he seems to be operating under the rules: "There exists X, such that for each region and for every streak of the line through the region, digits along the streak sum to X."

      To clarify, I was operating under the assumption that every region could have its own X. With that rule set I've nailed down the left center and left bottom region and restricted most others to 2 or 3 options.

      For reference, (SPOILER!)this is what it looks like so far. Colored cells are possible positions of the relevant region center, except bottom left, those are fixed and thus exploded to indicate the entire region.

      2 votes
  3. vektor
    Link
    I've found the ones where Simon struggles because the rules are weird and nothing like what he's used to are the best. To solve by yourself, that is. I feel this will be one of them. Compare also...

    I've found the ones where Simon struggles because the rules are weird and nothing like what he's used to are the best. To solve by yourself, that is. I feel this will be one of them. Compare also the skyscraper one. The fun, in my opinion, is in working from the rules to build a strategy for how to solve things, it's like novel mechanics in a video game. Applying those rules you built gets boring after a while, if those rules are good enough.

    That said, they are tough as old boots, sometimes. But so is basically every puzzle on CTC.

    2 votes