Day 1: Historian Hysteria
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1 point
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I have another Kotlin (albeit similar) solution:
import kotlin.math.abs
fun main() {
fun getLists(input: List<String>): Pair<List<Int>, List<Int>> {
val unsortedPairs = input.map {
it.split(" ").map { it.toInt() }
}
val listA = unsortedPairs.map { it.first() }
val listB = unsortedPairs.map { it.last() }
return Pair(listA, listB)
}
fun part1(input: List<String>): Int {
val (listA, listB) = getLists(input)
return listA.sorted().zip(listB.sorted()).sumOf { abs(it.first - it.second) }
}
fun part2(input: List<String>): Int {
val (listA, listB) = getLists(input)
return listA.sumOf { number ->
number * listB.count { it == number }
}
}
// Or read a large test input from the `src/Day01_test.txt` file:
val testInput = readInput("Day01_test")
check(part1(testInput) == 11)
check(part2(testInput) == 31)
// Read the input from the `src/Day01.txt` file.
val input = readInput("Day01")
part1(input).println()
part2(input).println()
}
It’s a bit more compact. (If you take out the part that actually calls the functions on the (test-)input.)
2 points