[Community Puzzle] Lumen


Same thing here, even after removing anything fancy, just using a couple for loops. All tests pass, but validators 5 and 6 fail. No idea why.


Don’t forget that the light goes in every direction :


with a light of 4 will become

2 2 2 2 2
2 3 3 3 2
2 3 4 3 2
2 3 3 3 2
2 2 2 2 2


Just a little suggestion: think before code. It wasn’t asked how strong the light on each cell is. You only need to know which cells have any light (or more accurately: how many cells are totally dark). If you consider this, it’ll be a pretty easy puzzle, no real need for recursion, BFS or anything special :slight_smile:

Happy coding!


Thanks for that neat little puzzle that showed once again that the simplest solution is in most cases also the best.


Thanks for that puzzle. A friend gave me a new idea to determinate light level and it solved 5 and 6 problems. (Java)


Finally i found it !
my problem was not about comprehension of the problem, but about how i evaluate the distance between candles and cells. I try the classic sqrt((x1-x2)²+(y1-y2)²) and this solution works surprisingly well on all the test cases except validation 5 and 6… I hope it will help !


Have to say I enjoyed this puzzle.

I didn’t use recursion as much as a few nested loops after identifying light sources, intensities, and cellar bounds.

I agree that this feels like the top end of the easy level in so far as my prior experiences go with these puzzles.

While I realized that light intensities don’t necessarily have to play a part here, I think it was interesting to consider when putting up the solution.


LOL nice that i find one like me


It has to play a role! it should differ if l=2 or =3 it makes a different what u mean by
don’t necessarily have to play a part here :thinking:


Sorry for the confusion. I agree that it plays a part, but I meant that the end result is determining how many areas have 0 light, so theoretically if you create a process just indicating where light exists vs where it doesn’t I think you can still put out a similar solution.


Hey, I’m having the same problem with the validator not accepting challenges 5 and 6 (In the IDE all challenges are fully completed).
Can I show one of you guys my Python code? Thx <3


Could you please explain the same in detail. Thanks!!


maybe i get it when i find the solution :smiley: thx


Nice easy puzzle. As written in a previous message - keeping it simple here is the best approach, and indeed no need to consider light intensity (although it was nice as part of the D&D description…)

Thinking about the original premise a bit more - I can see here the potential for a bit harder puzzle, that will ask you to find a path between two points in the room where you get the least accumulated light