Solution 2018-16, part 1 (Chronal Classification)

Author: rhaendel

src/main/kotlin/de/ronny_h/aoc/year2018/day16/ChronalClassification.kt

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+package de.ronny_h.aoc.year2018.day16
+
+import de.ronny_h.aoc.AdventOfCode
+import de.ronny_h.aoc.extensions.collections.split
+
+fun main() = ChronalClassification().run(531, 0)
+
+class ChronalClassification : AdventOfCode<Int>(2018, 16) {
+    override fun part1(input: List<String>): Int {
+        val samples = input.parseCPUSamples()
+        val device = WristDevice()
+        return device.behaveLikeNumberOfOpcodes(samples).filter { it > 2 }.size
+    }
+
+    override fun part2(input: List<String>): Int {
+        return 0
+    }
+}
+
+class WristDevice {
+    private val registers = mutableListOf(0, 0, 0, 0)
+
+    private val addr = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] + registers[inB]
+    }
+
+    private val addi = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] + inB
+    }
+
+    private val mulr = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] * registers[inB]
+    }
+
+    private val muli = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] * inB
+    }
+
+    private val banr = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] and registers[inB]
+    }
+
+    private val bani = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] and inB
+    }
+
+    private val borr = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] or registers[inB]
+    }
+
+    private val bori = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA] or inB
+    }
+
+    private val setr = { inA: Int, _: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = registers[inA]
+    }
+
+    private val seti = { inA: Int, _: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = inA
+    }
+
+    private val gtir = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = if (inA > registers[inB]) 1 else 0
+    }
+
+    private val gtri = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = if (registers[inA] > inB) 1 else 0
+    }
+
+    private val gtrr = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = if (registers[inA] > registers[inB]) 1 else 0
+    }
+
+    private val eqir = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = if (inA == registers[inB]) 1 else 0
+    }
+
+    private val eqri = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = if (registers[inA] == inB) 1 else 0
+    }
+
+    private val eqrr = { inA: Int, inB: Int, outC: Int, registers: MutableList<Int> ->
+        registers[outC] = if (registers[inA] == registers[inB]) 1 else 0
+    }
+
+    private val operations =
+        listOf(addr, addi, mulr, muli, banr, bani, borr, bori, setr, seti, gtir, gtri, gtrr, eqir, eqri, eqrr)
+
+    fun behaveLikeNumberOfOpcodes(samples: List<CPUSample>) =
+        samples.map { sample ->
+            operations.count { op ->
+                val registers = sample.registersBefore.toMutableList()
+                op(sample.a, sample.b, sample.c, registers)
+                registers == sample.registersAfter
+            }
+        }
+}
+
+fun List<String>.parseCPUSamples(): List<CPUSample> {
+    return buildList {
+        for (block in split()) {
+            if (!block.first().startsWith("Before")) {
+                break
+            }
+            val registersBefore = block[0].parseRegister("Before: ")
+            val operation = block[1].split(" ").map(String::toInt)
+            val registersAfter = block[2].parseRegister("After:  ")
+            add(CPUSample(registersBefore, operation[0], operation[1], operation[2], operation[3], registersAfter))
+        }
+    }
+}
+
+private fun String.parseRegister(prefix: String) =
+    substringAfter("$prefix[").substringBefore("]").split(", ").map(String::toInt)
+
+data class CPUSample(
+    val registersBefore: List<Int>,
+    val opcode: Int,
+    val a: Int,
+    val b: Int,
+    val c: Int,
+    val registersAfter: List<Int>
+)

src/test/kotlin/de/ronny_h/aoc/year2018/day16/ChronalClassificationTest.kt

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+package de.ronny_h.aoc.year2018.day16
+
+import de.ronny_h.aoc.extensions.asList
+import io.kotest.core.spec.style.StringSpec
+import io.kotest.matchers.shouldBe
+
+class ChronalClassificationTest : StringSpec({
+
+    val input = """
+            Before: [3, 2, 1, 1]
+            9 2 1 2
+            After:  [3, 2, 2, 1]
+
+            Before: [3, 2, 1, 1]
+            9 2 1 2
+            After:  [3, 2, 2, 1]
+
+
+
+            7 3 2 0
+            7 2 1 1
+            7 1 0 3
+            8 1 0 1
+        """.asList()
+
+    "input can be parsed" {
+        input.parseCPUSamples() shouldBe listOf(
+            CPUSample(listOf(3, 2, 1, 1), 9, 2, 1, 2, listOf(3, 2, 2, 1)),
+            CPUSample(listOf(3, 2, 1, 1), 9, 2, 1, 2, listOf(3, 2, 2, 1)),
+        )
+    }
+
+    "the given sample behaves like three opcodes" {
+        WristDevice().behaveLikeNumberOfOpcodes(
+            listOf(
+                CPUSample(listOf(3, 2, 1, 1), 9, 2, 1, 2, listOf(3, 2, 2, 1))
+            )
+        ) shouldBe listOf(3)
+    }
+
+    "part 1: both of the given samples behave like three opcodes" {
+        ChronalClassification().part1(input) shouldBe 2
+    }
+
+    "part 2" {
+        val input = listOf("")
+        ChronalClassification().part2(input) shouldBe 0
+    }
+})