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Day 25: Full of Hot Air

Puzzle description​

https://adventofcode.com/2022/day/25

Final Code​

def part1(input: String): String =
  totalSnafu(input)

val digitToInt = Map(
  '0' -> 0,
  '1' -> 1,
  '2' -> 2,
  '-' -> -1,
  '=' -> -2,
)
val intToDigit = digitToInt.map(_.swap)

def showSnafu(value: Long): String =
  val reverseDigits = Iterator.unfold(value)(v =>
    Option.when(v != 0) {
      val mod = math.floorMod(v, 5).toInt
      val digit = if mod > 2 then mod - 5 else mod
      intToDigit(digit) -> (v - digit) / 5
    }
  )
  if reverseDigits.isEmpty then "0"
  else reverseDigits.mkString.reverse

def readSnafu(line: String): Long =
  line.foldLeft(0L)((acc, digit) =>
    acc * 5 + digitToInt(digit)
  )

def totalSnafu(input: String): String =
  showSnafu(value = input.linesIterator.map(readSnafu).sum)

Run it in the browser​

Part 1 (Only 1 part today)​

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