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Comments on Puzzle #33975: Shadow
By Ashley (Queen Ashley)

peek at solution       solve puzzle
  quality:   difficulty:   solvability: moderate lookahead  

Puzzle Description Suppressed:Click below to view spoilers

#1: Claudia (clau_bolson) on Apr 29, 2020 [HINT]

I had to guess the entire right part
#2: Ashley (Queen Ashley) on Apr 30, 2020
when testing it i found that it was possible, though hard, to determine it through logic. it may have helped that i already knew what it would look like though.
#3: Emily Brower (Emimonster) on Apr 30, 2020 [HINT]
I had just a few dots and a black on the right side before I was feeling like it was trial and error.
So I counted up the numbers on the rows for the 3 sections:
24
23
22
And I counted up the numbers on the top. Because the remaining clues in the rows are only 1 number each row with no 1s it seems like everything has to be a solid connected line, so either a / or a \. To make the column numbers add up to each of the 3 sections' rows numbers, it means each row of column numbers lines up with its corresponding row sections, with the right-most 1 having to be in the middle section.
So then I just made each of the 3 sections into individual puzzles, which all worked with line logic apart from the bottom one, which only worked because I again presume that it will not work unless it is either a / or a \, which allows me to put in enough dots to make it work with line logic.

Just extrapolating the "/ or \" nature of it seems like very deep lookahead to me but I could be wrong. Either way the difficulty difference between the left and right halves is very large.

Don't think it matters, kedo, watashi mo kono kanji mou wakattita.
#4: BlackCat (BlackCat) on May 4, 2020
Nice. Did have to guess twice.
#5: Andrew Schultz (blurglecruncheon) on Feb 1, 2024 [HINT]
I used Emily's observations, but I did find some details I think we need to check for a rigorous proof/non-guessing solution.

But her intuition gets us most of the way there & I've seen people use the summing-dots approach for when there's just one box & I wouldn't blame someone for making that assumption and proceeding. It's a fun/interesting enough challenge then.

Here here we need to make sure that we can't have 2 or 0 of any column from 18-25 in any of R3-8, R11-16, R19-25.

This can be verified with moderate lookahead, nothing too many steps ahead, but there are a few columns to check!

In R3-8C18-25 it's not hard to show with moderate lookahead that we can't have 2 lines from the same column in C18-25.

That means the maximum possible is 25 if you count the columns (including C26) and 24 if you count the rows. But if one column of 18-25 has nothing in R3-8 then you have a maximum of 23 even with C26 being 1.

So there's exactly one column and row of dots in the upper right box. Also, counting dots, C26 R3-8 must be dots so columns = rows = 24. This lets us fill in the upper square with line logic.

Then I chipped away at C18 in the middle square. R11-12-13 are dots by edge logic. Then I said, what if the 2's in C18 are in R19-25? This got a quick contradiction with the upper 2, as you get a case where the 3 in C19 creates a 1 in a row.

This places a black dot at C18R20. Line logic for the middle box.

Edge logic on R19 and R25 places dots in C22--the 3x3 boxes quickly give contradictions wherever the 3's are in R19 and R25.

Then edge logic makes C18R20 a dot. It it is not, then R23C21/24 are black dots, a contradiction.

Line logic.
#6: Web Paint-By-Number Robot (webpbn) on Feb 1, 2024
Found to be solvable with moderate lookahead by blurglecruncheon.

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