day 14, part 1 solution

Author: mlcohen

.idea/gradle.xml

@@ -0,0 +1,11 @@
+plugins {
+    id("org.adventofcode.kotlin-application-conventions")
+}
+
+dependencies {
+
+}
+
+application {
+    mainClass.set("org.adventofcode.AppKt")
+}

day14/build.gradle.kts

@@ -0,0 +1,38 @@
+package org.adventofcode
+
+import java.io.File
+
+val RULE_REGEX_PATTERN = """([\w]+) -> ([\w])""".toRegex()
+
+fun runSolutionPart1(template: String, rules: Map<String, String>) {
+    println("Day 14 Solution: Part 1 (Basic Implementation)")
+    val steps = 10
+    val polymer = (0 until steps).fold(template) { polymer, _ ->
+        polymer
+            .windowedSequence(2)
+            .mapNotNull { rules[it]?.let { elem -> "${it[0]}$elem${it[1]}" } }
+            .mapIndexed { idx, chunk -> if (idx == 0) chunk else chunk.substring(1) }
+            .joinToString("")
+    }
+    val charCounts = polymer.asSequence().fold(mapOf<Char, Int>()) { map, char ->
+        map + (char to map.getOrDefault(char, 0) + 1)
+    }
+    val mostCommonCharCount = charCounts.maxOf { (_, count) -> count }
+    val leastCommonCharCount = charCounts.minOf { (_, count) -> count }
+    val score = mostCommonCharCount - leastCommonCharCount
+
+    println("Most common char count: $mostCommonCharCount")
+    println("Least common char count: $leastCommonCharCount")
+    println("Score: $score")
+}
+
+fun main() {
+    val input = File("day14/src/main/resources/puzzleInput.txt").readLines()
+    val template = input.first()
+    val rules = input.drop(2).mapNotNull {
+        val result = RULE_REGEX_PATTERN.matchEntire(it)
+        result?.groupValues?.let { (_, fromPair, toChar) -> fromPair to toChar }
+    }.toMap()
+
+    runSolutionPart1(template, rules)
+}

day14/src/main/kotlin/org/adventofcode/App.kt

@@ -0,0 +1,102 @@
+PBVHVOCOCFFNBCNCCBHK
+
+FV -> C
+SS -> B
+SC -> B
+BP -> K
+VP -> S
+HK -> K
+FS -> F
+CC -> V
+VB -> P
+OP -> B
+FO -> N
+FH -> O
+VK -> N
+PV -> S
+HV -> O
+PF -> F
+HH -> F
+NK -> S
+NC -> S
+FC -> H
+FK -> K
+OO -> N
+HP -> C
+NN -> H
+BB -> H
+CN -> P
+PS -> N
+VF -> S
+CB -> B
+OH -> S
+CF -> C
+OK -> P
+CV -> V
+CS -> H
+KN -> B
+OV -> S
+HB -> C
+OS -> V
+PC -> B
+CK -> S
+PP -> K
+SN -> O
+VV -> C
+NS -> F
+PN -> K
+HS -> P
+VO -> B
+VC -> B
+NV -> P
+VS -> N
+FP -> F
+HO -> S
+KS -> O
+BN -> F
+VN -> P
+OC -> K
+SF -> P
+PO -> P
+SB -> O
+FN -> F
+OF -> F
+CP -> C
+HC -> O
+PH -> O
+BC -> O
+NO -> C
+BH -> C
+VH -> S
+KK -> O
+SV -> K
+KB -> K
+BS -> S
+HF -> B
+NH -> S
+PB -> N
+HN -> K
+SK -> B
+FB -> F
+KV -> S
+BF -> S
+ON -> S
+BV -> P
+KC -> S
+NB -> S
+NP -> B
+BK -> K
+NF -> C
+BO -> K
+KF -> B
+KH -> N
+SP -> O
+CO -> S
+KO -> V
+SO -> B
+CH -> C
+KP -> C
+FF -> K
+PK -> F
+OB -> H
+SH -> C

day14/src/main/resources/puzzleInput.txt

@@ -0,0 +1,18 @@
+NNCB
+
+CH -> B
+HH -> N
+CB -> H
+NH -> C
+HB -> C
+HC -> B
+HN -> C
+NN -> C
+BH -> H
+NC -> B
+NB -> B
+BN -> B
+BB -> N
+BC -> B
+CC -> N
+CN -> C

day14/src/main/resources/sampleInput.txt

@@ -22,4 +22,5 @@ include(
     "day11",
     "day12",
     "day13",
+    "day14",
 )