On the left a horizontal must start with F: F.[AO].[AO].*
However, the diagonal for that cell may not include an F (aside from the start): [^X]*(DN|TE|NI)
Because it's so trivially unsolvable, I had a quick look at the posted solution.
We're reading it wrong.
Take the first regex on the top row, one you included in your example:
[^X]*(DN|TE|NI)
You're supposed to fill that in from the bottom to the top.
In other words, the first letter goes immediately to the right of [^c]*[^R]*III.* - that square has to be a 'not X'. The hex immediately below it has to be an E, I, or N.
a022311•4d ago
I think I've seen this puzzle before, but I really enjoyed myself gradually solving it while doing other things in the last two hours. I'm sharing this for anyone else who wants a way to spend their afternoon!
[1]: https://regexle.com
hdjrudni•11h ago
Took 4.5 min to solve #519. Would have been quicker if I started with a better strategy but it was my first time.
Levitating•9h ago
I thought the bigger one was more fun though, I'll continue with that one now.
hughes•8h ago
GordonS•39m ago
#520 seems much harder tho!
What a great game, just wish the colours were configurable (colour blind)!