Tents

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

Post by pinkagape » Sun 12 Sep, 2021 7:37 pm

Tents is a puzzle with relatively simple rules. Rohan Rao gives the rules as following on his blog:

Place one tent horizontally or vertically next to each tree. Tents do not touch each other, not even diagonally. The numbers outside the grid indicate the number of tents in the corresponding row/column.

Techniques can vary, but the following walkthrough gives some useful techniques to start off with.

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I like to mark crosses in cells which are not adjacent to any trees, as there can't be any tents here.

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The makes the 2 over the first column very useful, as both remaining squares must contain tents. The top tent is clear which tree it matches with, the bottom one less so. It can be useful to label these connections.

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One very frequently used rule is that tents cannot touch each other, so we can cross out a lot of other cells now we know where these tents are.

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This also left just two cells on the top row, so I filled in those cells with tents, and it was also clear where they connected. The tree in row 4, column 2 now only has one cell it can have its tent in.

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The last tree (row 4 column 4) can't have its tent up or down as then it would touch another tent, so it must go right, and we're done.

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pinkagape
Posts:237
Joined:Mon 30 Apr, 2012 4:11 pm

Re: Tents

Post by pinkagape » Sun 12 Sep, 2021 7:38 pm

Here are two more examples

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pinkagape
Posts:237
Joined:Mon 30 Apr, 2012 4:11 pm

Re: Tents

Post by pinkagape » Mon 04 Oct, 2021 6:53 pm

And two more examples that I wrote for you today.

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Note that the puzzle on the right is broken but has been discussed and replaced below.
Last edited by pinkagape on Wed 06 Oct, 2021 7:23 pm, edited 1 time in total.

detuned
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Re: Tents

Post by detuned » Mon 04 Oct, 2021 10:10 pm

Thanks for the post Adam. I do feel duty bound to make a post saying the phrasing of the rules: “tents don’t touch each other, not even diagonally” fails to stand up to even the most basic scrutiny, and can very easily be improved upon :) my suggestion is:

"different tents must not be placed in cells that share either an edge or a corner."

DavidC
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Joined:Wed 03 Nov, 2010 9:34 pm

Re: Tents

Post by DavidC » Tue 05 Oct, 2021 12:30 pm

Silly question time. I am confused by the bottom of the second new example. To achieve the required 3 tents in row 6, the only three trees that reach them orthogonally are r6c2, r6c4 and r7c7. r7c7 puts a tent in r6c7 which drives the other two to be in c1 and c4 to avoid tents touching. Then, because the tree at r5c5 is blocked vertically by other trees, its tent must be in r5c4 or r5c6 ... but both are touched by the tents at r6c4 and r6c7. Please can someone explain my stupid error. Thanks.

pinkagape
Posts:237
Joined:Mon 30 Apr, 2012 4:11 pm

Re: Tents

Post by pinkagape » Wed 06 Oct, 2021 4:00 am

No error there David, from you, it’s my broken puzzle. I had a disappointing number of broken puzzles in my first Tents set which went for testing. I’ve done it again. I’ll replace the puzzle tonight.

pinkagape
Posts:237
Joined:Mon 30 Apr, 2012 4:11 pm

Re: Tents

Post by pinkagape » Wed 06 Oct, 2021 4:02 am

detuned wrote:
Mon 04 Oct, 2021 10:10 pm
Thanks for the post Adam. I do feel duty bound to make a post saying the phrasing of the rules: “tents don’t touch each other, not even diagonally” fails to stand up to even the most basic scrutiny, and can very easily be improved upon :) my suggestion is:

"different tents must not be placed in cells that share either an edge or a corner."
Fair point. I’ll use this wording on the competition set. Thanks Tom.

pinkagape
Posts:237
Joined:Mon 30 Apr, 2012 4:11 pm

Re: Tents

Post by pinkagape » Wed 06 Oct, 2021 7:22 pm

Here is a replacement for the broken puzzle.

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DavidC
Posts:217
Joined:Wed 03 Nov, 2010 9:34 pm

Re: Tents

Post by DavidC » Thu 07 Oct, 2021 9:48 am

Great, thanks

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