AoC | Day 5 | Part 1

package year_2023.day_5

import kotlin.math.absoluteValue

fun partOne() {
    println("[2023] Day five, part one...")

    val inputData = input()

    fun getMap(mapName: String): List<Pair<LongRange, LongRange>> {
        val map = inputData.split("\n\n")
            .single { it.contains(mapName) }
            .substringAfter("$mapName map:")
            .trim()
            .split("\n")
            .map { it.split(" ") }
            .map {
                val startSource = it[1].toLong()
                val startTarget = it[0].toLong()
                val range = it[2].toLong()
                (startSource until startSource + range) to (startTarget until startTarget + range)
            }

        return map
    }

    val seeds = inputData.split("\n\n")[0]
        .substringAfter(":")
        .trim()
        .split(" ")
        .map { it.toLong() }


    val seedToSoilRanges = getMap("seed-to-soil")
    val soilToFertilizerRanges = getMap("soil-to-fertilizer")
    val fertilizerToWaterRanges = getMap("fertilizer-to-water")
    val waterToLightRanges = getMap("water-to-light")
    val lightToTemperatureRanges = getMap("light-to-temperature")
    val temperatureToHumidityRanges = getMap("temperature-to-humidity")
    val humidityToLocationRanges = getMap("humidity-to-location")

    val seedToLocationMap = mutableMapOf<Long, Long>()

    fun getNext(map: List<Pair<LongRange, LongRange>>, source: Long): Long {
        val ranges = map.firstOrNull { it.first.contains(source) }
            ?: return source

        return ranges.second.first + (source - ranges.first.first).absoluteValue
    }

    seeds.forEach { seed ->
        val soil = getNext(seedToSoilRanges, seed)
        val fertilizer = getNext(soilToFertilizerRanges, soil)
        val water = getNext(fertilizerToWaterRanges, fertilizer)
        val light = getNext(waterToLightRanges, water)
        val temperature = getNext(lightToTemperatureRanges, light)
        val humidity = getNext(temperatureToHumidityRanges, temperature)
        val location = getNext(humidityToLocationRanges, humidity)

        seedToLocationMap[seed] = location
    }

    println(seedToLocationMap.minBy { it.value }.value)
}