Help needed for day 14 :bangbang:

# advent-of-code

[kartikpatodi]

Help needed for day 14 ‼️

[kartikpatodi]

For getting all floating masks I tried it with recusion

private fun floatingMasksOf(mask: String): List<Mask> = when {
            mask.matches("""[01]+""".toRegex()) -> listOf(Mask(mask))
            else -> mutableListOf(
                floatingMasksOf(mask.replaceFirst('X', '0')),
                floatingMasksOf(mask.replaceFirst('X', '1'))
            ).flatten()
        }

[kartikpatodi]

How to avoid listOf and flatten .
I tried using generate sequence but it did not work

[Timmy]

plus ? As in

floatingMasksOf(mask.replaceFirst('X', '0')) +
floatingMasksOf(mask.replaceFirst('X', '1'))

[Timmy]

The first listOf is unavoidable I think (or at least I am fine with it)

[kartikpatodi]

Can generateSequence be used here?

[Timmy]

You can use the sequence {} builder (https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/sequence.html) with yield instead of listOf and yieldAll for both recursive calls. Not sure about generateSequence

[Timmy]

https://pl.kotl.in/vv08YCacx

[kartikpatodi]

Thanks @Timmy