count from left, then count from right to see which squares have to be marked no matter what. so e.g. in the 6 11 line, count 6 from the left, leave a gap, count 11, then from the right do 11, then 6.

Originally posted by PL-BR:

count from left, then count from right to see which squares have to be marked no matter what. so e.g. in the 6 11 line, count 6 from the left, leave a gap, count 11, then from the right do 11, then 6.

Thanks for your Answer!
Did i do it right?
https://imgur.com/a/GsW8Zq5

almost. you shouldn't mark the middle 4 cells. by overlap I meant within the same number, so count 6 from the left, then 11-gap-6 from the right and see which part of the 6 overlap, then do 6-gap-11 from the left and 11 from the right to see which cells within the 11 section overlap.

also, in the middle you already have a bunch of cells colored, you can work with those as well. e.g. in the 5 3 3 2 1 1 column you have the 3rd cell marked, that's obviously part of the 5, so you can mark cell 4 and 5 too because it has to reach at least that far (if it starts from the first cell, which you don't know yet).