Sudoku Adventure #1193 - "Alpine Snowboarding" by Gene

Added: 2026-05-29

[00:00:00]Hello, let's continue our Sudoku adventure with Alpine Snowboarding by Jean.

[00:00:04]So, we have normal 6 by 6 Sudoku rules.

[00:00:06]That means in each row, each column, and each 2 by 3 box, we are placing the digits 1 to 6 exactly once each.

[00:00:13]We also have these German Whisper lines.

[00:00:15]That's well, a single one. It's a green line here. Adjacent digits on the line have to have a difference of at least three.

[00:00:23]So, these two have a difference of at least three, these two, these two, etc. So, they're kind of overlapping in that way.

[00:00:29]So, if there was, for example, a two here, this digit, which is adjacent to it, needs to have be at least a five or a six. Like, a four minus two is only two. If you have a number smaller, just it's just the larger minus the smaller.

[00:00:43]So, one is also not at least three.

[00:00:46]Um but, you know, five to two and two to five are the same difference of three.

[00:00:51]All right. We also have these blue lines in the grid. These are region sum lines.

[00:00:55]What you do is I'll I'll use this one as an example.

[00:00:58]Um every time it crosses a box boundary, we form a new segment. So, we can call this the green segment, the purple segment, and the orange segment.

[00:01:09]So, just when you leave the box, you form you start a new segment.

[00:01:13]And the sum of each segment on the same line is the same. So, we have the same sum on every segment that is on the same line.

[00:01:22]So, this sum might be different than these sums, but this sum is the same as this sum, which is the same as this sum. So, if this was, say, 1 2 4, that adds to seven. This could be 2 4 1, also adding to seven. And this could be uh 2 5. That adds to seven.

[00:01:38]And that's it. Those are the rules.

[00:01:40]There's a link in the description if you'd like to try the puzzle yourself.

[00:01:43]And I'm going to get started right now.

[00:01:46]Okay.

[00:01:48]I'm going to start by coloring this German Whisper line.

[00:01:53]And also, we can note that this line here, it's really um it's interesting. This digit is the same as this digit and that's the sum of these two.

[00:02:03]So, let's think about this for a second.

[00:02:05]So, I'm going to color this line first.

[00:02:07]We'll use um green and purple.

[00:02:10]Now, what am I doing here? I'm representing the fact that German whisper lines always alternate between low and high. If this was a low digit, 1 2 or 3, we cannot be next to another low digit cuz the max difference would be two. 3 - 1 is 2. So, we can jump up to a high digit and then next to a high digit we can't put another high digit. We have to go back down to low. So, we don't know if green is low or high, but we do know that it alternates.

[00:02:33]So, we know that these both of these digits are the same low or high.

[00:02:41]Uh this but we know that they aren't the same digit because this is the sum of these two.

[00:02:48]That means that this digit here can't exceed two because if this was the lowest it could possibly be as a one, this then would be the um highest it could possibly be, which is three, and one to three as a difference of two.

[00:03:04]So, that's one or two. Now, the other thing I'm noticing is that neither of these can actually be a three because a three has only one buddy, which is the six. So, we'd have to put a six next to it. But, also here we'd have to put a six next to it and those sixes would share a column. Here, the sixes would share a row. So, actually these are from one two and we know this one is smaller.

[00:03:28]I'm a little bit worried about the fact that this would be a two.

[00:03:33]Right, so it just can't be low, right?

[00:03:36]We just proved it can't be low because these would have to be one or two and then this would have to be the difference between them, but the difference between them would be one, right? So, this would be one, this this would be one, this would be two and the difference between them would be one because these two need to add to that.

[00:03:52]We we do that. So, they need to be high.

[00:03:54]And for high digits, it means they're not fours, cuz four has only one buddy, which is double one. It's kind of symmetric in that way.

[00:04:01]And so, these are from five or six. This is the lower one, so this is five, this is six, and this is the one in order to get them to add. So, now that I know that green is high, I'm going to make that orange.

[00:04:13]And then purple's blue for low. I just like that. Um I think for now I will color every cell.

[00:04:21]We should all stick with it. This is also a six cuz of the region sum line, and that is high.

[00:04:26]Okay.

[00:04:29]So, we know that this is a four or six.

[00:04:31]Now, it actually can't be a four cuz it would have to be next to a one, and the one is taken. So, that's a six as well.

[00:04:37]This is not a four because of the same uh issue with double ones. So, this is the five.

[00:04:44]This is a five or six, and this could have be a four or five or five because four would put double one, but that's okay.

[00:04:51]Um This is a has to be next to a five, so it can't be a three, so it's a two. In fact, this was never a three.

[00:05:00]This can't be a three cuz it's next to five, so it's a one.

[00:05:05]It can't be two, either.

[00:05:07]This is a two or three, meaning it can't be four cuz it's not next to one. So, that is a five.

[00:05:12]That's a six. Five can't be next to three, so that's a two. Right, it was never going to be three.

[00:05:17]Um this is a one or a two.

[00:05:20]This is a one or a two, and this is a one or a two cuz they're all next to fives.

[00:05:25]All righty.

[00:05:28]Hm.

[00:05:30]That was a lot, but I think we need to think about this line a bit more.

[00:05:34]So, what's the maximum this can add to now? Because five and six are used, so a three-four pair is the highest it can be.

[00:05:41]Which means it adds to either six or seven, because three cells that can't repeat, the minimum is one, 2 3, which adds to six. So, our minimum sum is six according to these, and our maximum sum is seven according to this.

[00:05:54]So, six or seven. Now, how would we add to six?

[00:05:57]We can't do 1 + 5. We can't do 2 + 4.

[00:05:59]So, we can't add to six. So, we do add to seven with 3 4. That puts the um What's missing? The one here.

[00:06:07]It's interesting. We can't use the one cuz we'd add to four or five.

[00:06:11]Um so, since we add to seven, my example's cracked. These are from 1 2 4.

[00:06:15]So, that's a four. That's two. That's one. That's two, and that's one.

[00:06:19]Um I don't need the colors anymore.

[00:06:22]Um these two are two four pair. We know that this is four and this is two. The only way to add to seven and three is 1 2 4.

[00:06:28]Um This is not a four. So, this is a three.

[00:06:31]That's a four. That's a three.

[00:06:33]All right. Making good progress. I think we're basically wrapping up now. These two digits are a three and a five. This is three. This is five. This column finishes with one. This column finishes with a four and a six.

[00:06:44]This digit here is a five. This digit here is a three. This digit's a three.

[00:06:49]Here, we need the four and the six.

[00:06:50]That's four, and that's six. Here, we need the four. And then up here, we need a two, three, and five. This is five.

[00:06:57]This is three. This is two.

[00:06:59]All right. Nice puzzle, Jean.

[00:07:01]Um I enjoyed that, actually. That uh nice >> [sighs] >> uh nice straightforward um puzzle once you once you know kind of how German whispers work.

[00:07:11]Um it kind of falls into place. And I I liked this I liked how this determined lower versus high. That was neat. Where this couldn't be a 1 2 pair because this would also have to be a one. That was really cool.

[00:07:21]All right. Well, how do you do?