Coverage Summary for Class: Day04p2Kt (day04p2)

 package day04p2
 
 
 data class PileOfScratchcards(val cards: List<Scratchcard>) {
   fun countTotalNumberOfOwnedScratchcards(): Int {
     val numOfCardsOwnedByEachCard = Array(cards.size) { 1 }
     cards.forEachIndexed { i, card ->
       val num = numOfCardsOwnedByEachCard[i]
       for (j in i + 1 until i + 1 + card.numOfOwnedWinningNumbers) {
         numOfCardsOwnedByEachCard[j] += num
       }
     }
     return numOfCardsOwnedByEachCard.sum()
   }
 
   companion object {
     fun from(raw: String): PileOfScratchcards =
       PileOfScratchcards(raw.lineSequence().map { Scratchcard.from(it) }.toList())
   }
 
 }
 
 data class Scratchcard(val id: Int, val winningNumbers: Set<Int>, val ownedNumbers: Set<Int>) {
   val numOfOwnedWinningNumbers: Int = winningNumbers.intersect(ownedNumbers).size
 
   companion object {
     private val cardRegex = """Card \s*(\d+): (.+) \| (.+)""".toRegex()
 
     fun from(raw: String): Scratchcard {
       val (id, winningNumbers, ownedNumbers) = cardRegex
         .matchEntire(raw)?.destructured ?: error("no match for $raw")
 
       return Scratchcard(
         id.toInt(),
         winningNumbers.toIntSet(),
         ownedNumbers.toIntSet()
       )
     }
   }
 }
 
 private val intRegex = """(\d+)""".toRegex()
 
 fun String.toIntSet(): Set<Int> =
   intRegex.findAll(this).map { it.value.toInt() }.toSet()