56 lines
1.5 KiB
Text
56 lines
1.5 KiB
Text
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#!/usr/bin/env kotlin
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import java.io.File
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import kotlin.math.floor
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// I LOVE MATH
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typealias Matrix2 = Pair<Pair<Int, Int>, Pair<Int, Int>>
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fun Matrix2.determinant(): Int = (this.first.first * this.second.second) - (this.first.second * this.second.first)
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typealias Point = Pair<Int, Int>
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data class Game(
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val buttonA: Point,
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val buttonB: Point,
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val goal: Point
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)
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val games = File("input.txt").readLines().chunked(4).map { lines ->
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Game(
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buttonA = lines[0].substring(12).split(", Y+").let {
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it[0].toInt() to it[1].toInt()
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},
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buttonB = lines[1].substring(12).split(", Y+").let {
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it[0].toInt() to it[1].toInt()
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},
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goal = lines[2].substring(9).split(", Y=").let {
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it[0].toInt() to it[1].toInt()
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}
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)
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}
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var tokens = 0
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games.forEach { game ->
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val aPresses = Matrix2(
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game.goal.first to game.buttonB.first,
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game.goal.second to game.buttonB.second
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).determinant().toDouble() / Matrix2(
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game.buttonA.first to game.buttonB.first,
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game.buttonA.second to game.buttonB.second
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).determinant()
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val bPresses = Matrix2(
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game.buttonA.first to game.goal.first,
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game.buttonA.second to game.goal.second
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).determinant().toDouble() / Matrix2(
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game.buttonA.first to game.buttonB.first,
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game.buttonA.second to game.buttonB.second
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).determinant()
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if (aPresses != floor(aPresses) || bPresses != floor(bPresses)) return@forEach
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tokens += aPresses.toInt() * 3 + bPresses.toInt()
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}
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println("Result: $tokens")
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