hubert/Advent-of-Code
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Clean a bit

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Hubert Van De Walle 2020-12-08 07:54:37 +01:00
parent 7d8db7b493
commit ee2dfbd40b
1 changed files with 22 additions and 15 deletions
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37
days/src/main/kotlin/Day08.kt
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@ -10,22 +10,21 @@ import org.eclipse.collections.impl.factory.primitive.IntSets
@Day(8) @Day(8)
class Day08(@Lines val input: Input<List<String>>) { class Day08(@Lines val input: Input<List<String>>) {
private val instructions = input.value private val instructions = input.value.map {
.map { val words = it.split(" ")
val words = it.split(" ") Instruction(Operation.valueOf(words[0].capitalize()), words[1].toInt())
Instruction(Operation.valueOf(words[0].capitalize()), words[1].toInt()) }.toTypedArray()
}.toTypedArray()
fun part1() = run(instructions) fun part1() = run(instructions)
private fun run(mutatedInstructions: Array<Instruction>): Int { private fun run(instructions: Array<Instruction>): VmResult {
var acc = 0 var acc = 0
var ptr = 0 var ptr = 0
val visited = IntSets.mutable.empty() val visited = IntSets.mutable.empty()
while (visited.add(ptr)) { while (visited.add(ptr)) {
val instruction = mutatedInstructions[ptr] val instruction = instructions[ptr]
when (instruction.operation) { when (instruction.operation) {
Operation.Acc -> { Operation.Acc -> {
acc += instruction.argument acc += instruction.argument
@ -34,28 +33,31 @@ class Day08(@Lines val input: Input<List<String>>) {
Operation.Jmp -> ptr += instruction.argument Operation.Jmp -> ptr += instruction.argument
Operation.Nop -> ptr++ Operation.Nop -> ptr++
} }
if (ptr !in mutatedInstructions.indices) { if (ptr !in instructions.indices) {
println(acc) return VmResult.Terminated(acc)
error("oob")
} }
} }
return acc return VmResult.Looped(acc)
} }
fun part2() { fun part2(): VmResult {
val possibleMutations = IntLists.mutable.empty() val possibleMutations = IntLists.mutable.empty()
instructions.forEachIndexed { i, e -> instructions.forEachIndexed { i, e ->
if (e.operation != Operation.Acc) possibleMutations.add(i) if (e.operation == Operation.Jmp || e.operation == Operation.Nop) possibleMutations.add(i)
} }
possibleMutations.forEach { index -> for (index in possibleMutations.toArray()) {
val copy = instructions.clone().also { val copy = instructions.clone().also {
val modifiedOperation = if (it[index].operation == Operation.Nop) Operation.Jmp else Operation.Nop val modifiedOperation = if (it[index].operation == Operation.Nop) Operation.Jmp else Operation.Nop
it[index] = it[index].copy(operation = modifiedOperation) it[index] = it[index].copy(operation = modifiedOperation)
} }
run(copy)
val res = run(copy)
if (res is VmResult.Terminated) return res
} }
error("No result found")
} }
} }
@ -64,6 +66,11 @@ enum class Operation { Acc, Jmp, Nop }
data class Instruction(val operation: Operation, val argument: Int) data class Instruction(val operation: Operation, val argument: Int)
sealed class VmResult {
data class Looped(val acc: Int) : VmResult()
data class Terminated(val acc: Int) : VmResult()
}
fun main() { fun main() {
val day = createDay<Day08>() val day = createDay<Day08>()
println(day.part1()) println(day.part1())