Doppelblock
Doppelblock
I like Doppelblock. After speaking to Maurice about these puzzles, I realise I may have a limited toolbox for solving these, so I'd be keen to hear others' tips.
Here is my guide.
Here is my guide.
 Attachments

 Doppelblock Puzzle Guide.pdf
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Re: Doppelblock
Here are two examples I have for you to try, too. I'll try to show a larger one soon.
Edit: broken puzzle removed and replaced three posts down.
Edit: broken puzzle removed and replaced three posts down.
Last edited by pinkagape on Thu 08 Sep, 2022 7:26 pm, edited 1 time in total.
Re: Doppelblock
Can you please doublecheck your second example (33353,003), I get a contradiction when I solve it.
Re: Doppelblock
Thanks James. I think there’s an extra 3 in the first column which doesn’t work. It seems to work without the 3 for column 1. I’ll correct the image this evening.
Re: Doppelblock
Thanks for fixing that Adam.
In terms of learning, I'm curious about your solving thoughts for the second example.
After a quick start, I can find one digit and four blocks. Which way do you go next?
In terms of learning, I'm curious about your solving thoughts for the second example.
After a quick start, I can find one digit and four blocks. Which way do you go next?
Re: Doppelblock
When I was building it, I only got three blocks for certain before I had to start asking myself if this cell was this number, then what happens next?
I thought that R5C3 was the best bet for this, and it was enough to define the puzzle. I’m curious about your fourth block and I wonder if there’s a less plodding way of making the progress, but that was my intention.
I thought that R5C3 was the best bet for this, and it was enough to define the puzzle. I’m curious about your fourth block and I wonder if there’s a less plodding way of making the progress, but that was my intention.
Re: Doppelblock
In terms of the second example, this was my sticking point:
My approach here was to note that the 3 in C5 and the 3 in R5 interact through their common cell  either both clues are a 1length gap or both clues are a 2length gap.
This means that either both R3C5 and R5C3 are 3, in which case C3 has its blocks in R1 and R4, or neither of the aforementioned cells is a 3, in which case R2C5 is not a block, so R2C3 is a block and then, once again, R4C3 is a block.
In either case, R4C3 is a block, getting you to this point:
Now it still seems difficult to make progress, but there is a nice step. The 3 in C3 and the 3 in C5 cannot both be of the same length, because this would cause a clash of 3s in either R3 or in R5. So one of R3C3 and R3C5 is a 3, and one of R5C3 and R5C5 is a 3, which determines the remaining numbers in C4 since R3C4 can now not be a 3.
Then the orientation of C2 is determined and the puzzle proceeds more easily.
My approach here was to note that the 3 in C5 and the 3 in R5 interact through their common cell  either both clues are a 1length gap or both clues are a 2length gap.
This means that either both R3C5 and R5C3 are 3, in which case C3 has its blocks in R1 and R4, or neither of the aforementioned cells is a 3, in which case R2C5 is not a block, so R2C3 is a block and then, once again, R4C3 is a block.
In either case, R4C3 is a block, getting you to this point:
Now it still seems difficult to make progress, but there is a nice step. The 3 in C3 and the 3 in C5 cannot both be of the same length, because this would cause a clash of 3s in either R3 or in R5. So one of R3C3 and R3C5 is a 3, and one of R5C3 and R5C5 is a 3, which determines the remaining numbers in C4 since R3C4 can now not be a 3.
Then the orientation of C2 is determined and the puzzle proceeds more easily.
Re: Doppelblock
Nice idea Sam, thank you.
Spotting that R5 and C5 must have the same length gap  I'll keep my eye open for things like this in the future.
I also found a shortcut by using this in your first image: If R5 and C5 are both small gaps then you would have a 3 in R3C5 and also a 3 in R4C2, which breaks column 4. So the gaps are long, and the rest is quick.
Spotting that R5 and C5 must have the same length gap  I'll keep my eye open for things like this in the future.
I also found a shortcut by using this in your first image: If R5 and C5 are both small gaps then you would have a 3 in R3C5 and also a 3 in R4C2, which breaks column 4. So the gaps are long, and the rest is quick.
Re: Doppelblock
Here is a larger example where the values go from 1 to 5.