Doppelblock

Rules and Tips for standard puzzle types, and their variants
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pinkagape
Posts: 351
Joined: Mon 30 Apr, 2012 4:11 pm

Doppelblock

Post by pinkagape »

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.
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Doppelblock Puzzle Guide.pdf
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pinkagape
Posts: 351
Joined: Mon 30 Apr, 2012 4:11 pm

Re: Doppelblock

Post by pinkagape »

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.
Last edited by pinkagape on Thu 08 Sep, 2022 7:26 pm, edited 1 time in total.
kiwijam
Posts: 735
Joined: Wed 01 Jun, 2011 10:03 am

Re: Doppelblock

Post by kiwijam »

Can you please double-check your second example (33353,-00-3), I get a contradiction when I solve it.
pinkagape
Posts: 351
Joined: Mon 30 Apr, 2012 4:11 pm

Re: Doppelblock

Post by pinkagape »

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.
pinkagape
Posts: 351
Joined: Mon 30 Apr, 2012 4:11 pm

Re: Doppelblock

Post by pinkagape »

Here we go.

Image

Image
kiwijam
Posts: 735
Joined: Wed 01 Jun, 2011 10:03 am

Re: Doppelblock

Post by kiwijam »

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?
pinkagape
Posts: 351
Joined: Mon 30 Apr, 2012 4:11 pm

Re: Doppelblock

Post by pinkagape »

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.
Feadoor
Posts: 288
Joined: Thu 17 May, 2018 7:08 am

Re: Doppelblock

Post by Feadoor »

In terms of the second example, this was my sticking point:

Image

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 1-length gap or both clues are a 2-length 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:

Image

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.
kiwijam
Posts: 735
Joined: Wed 01 Jun, 2011 10:03 am

Re: Doppelblock

Post by kiwijam »

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.
pinkagape
Posts: 351
Joined: Mon 30 Apr, 2012 4:11 pm

Re: Doppelblock

Post by pinkagape »

Here is a larger example where the values go from 1 to 5.

Image
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