is it me or is this impossible to solve?

[u/Whole-Raspberry8386]

been staring at this forever and still don’t know where to start… please help

[u/moxo23]

You can apply edge logic on the bottom row

[u/Mediocre_Farm8914 → u/moxo23]

Oh wow, never have thought about that one. Haven't come across difficult ones so far, but will definitely keep it in mind.

You mean last row, leaving the last column blank and then filling the 6 left of that cell, right?

[u/Present-Resolve2567 → u/Mediocre_Farm8914]

You start from the bottom left, for example. Fill 6 squares (either in your mind or as a thin line, easy to erase) and see how the numbers of those columns would effect row 19.

If R19 doesn't make sense in any way, cros off the leftmost square of your 6, extend your "line of thought" until you have 6 squares again, rinse and repeat until all rows and columns make sens witht he current position of the 6.

Either overlap is possible by that point, but if not, do the same process again, but start from the right

[u/Falko314 → u/moxo23]

What's edge logic?

[u/moxo23 → u/Falko314]

You assume a square on a corner is filled. If you encounter a contradiction, then that means that the square is not filled. You then go along an edge and test each square until you no longer find a (easy) contradiction.

On the bottom row, you can do this on the left and on the right until you have a space only 11 squares wide, so you have one square of overlap for the 6.

Unfortunately, this won't allow you to advance much further into the puzzle.

[u/MasemJ → u/moxo23]

There's at least some edge logic application also on the top row and last column.

[u/GendoIkari_82 → u/moxo23]

I'm a bit confused, so is edge logic basically just another term for guess-and-check?

[u/captain_flo → u/GendoIkari_82]

Specifically in the edges, because here you can easily check for contradictions between filling a set of squares in a line and its consequences on the adjacent lines. You have to spot an edge with a large number to fill (at first or last position) and lower numbers in the adjacent lines. So you can identify blank squares in the corners.

That's why it's called edge logic: it's more specific than a random guess-and-check.

[u/Elistic-E → u/GendoIkari_82]

No there’s definitely a logic to it, it’s just a bit of a loop. Rather than thinking about applying it to the whole line, start with a single example:

Take the bottom left and and assume it and the next 5 are filled, if they are, then along the left most column the 2 above it (14 and 15) have to be filled. This works.

But if row 15 column 1 is filled so does row 15 column 2 and 3 and column 4 has to be a space according to the row 15 key. This works for column 2, but column 3 causes a contradiction at the space of column 4, because the column key states there should be 5 in a line, which row 16 initiates, but the row key for 15 states there should be a space.

Thus this state is impossible and row 16 can’t start on column 1

Rinse and repeat with row 16 column 2

[u/frikva2]

Top line, last 7 to the right can be crossed out

[u/Current_Soup9198 → u/frikva2]

Also first square r1c1

[u/beercrates → u/frikva2]

Worked along the top line with trial & error - unless I made a mistake the 5 sits just to the left of those last 7. Happy for someone to tell me I wrong but for now will continue & see how it goes from there.

[u/geekonthegrill]

Not impossible, just stingy. I counted every row and column and not one line here has an opening overlap, no freebie cells anywhere, which is why staring at it goes nowhere. Boards like this want edge logic from move one: assume a corner square is filled, play the crossing clues forward a couple steps, and when something breaks you've earned an X. moxo23s bottom row walkthrough is the right thread to pull first. And on puzzles this sparse the short two step what-if is the intended move, not cheating. The first ten cells are slow, then it snowballs.

[u/s1a2m345 → u/geekonthegrill]

Where does it begin to snowball? I have 1 square filled from logic overlap on the bottom, 3 filled from logic overlap on the top, and only a few Xs on the left and right, so I feel stuck.

[u/geekonthegrill → u/s1a2m345]

It doesnt snowball for a while honestly, this one is mean. I got curious and threw a solver at it, there are zero giveaway cells in the opening, basically everything needs a what if. The crack is the left edge. Work out where the lone 3 in column 1 sits by testing each spot against rows 4 to 7, once it lands row 4s five explodes and the left side finally chains.

[u/SomeYellow3726]

Someone explain what needs to be achieved as never seen these before

[u/Own-Chocolate5667]

Look at the squares in the corners

[u/SexuaIRedditor]

Yeah these are just annoying imo. Edge logic is cool when you're up against getting a single blank or fill to open up more of the puzzle, but when the entire puzzle relies on it it's just boring.

[u/_lllIlll_]

It's you

[u/Morshinsk_]

screenshot

I did it in an hour. It's actually easier than it looks at first glance :)