Day 14

Author: Kanialdo

src/day14/Day14.kt

@@ -0,0 +1,108 @@
+package day14
+
+import utils.verify
+import java.io.File
+
+/** https://adventofcode.com/2021/day/14 */
+
+fun main() {
+
+ val rootDir = File("src/day14/")
+
+ data class Insertion(val a: Char, val b: Char, val input: Char)
+ data class Data(val polymer: String, val rules: List<Insertion>)
+
+ fun Data.allPosibilities(): Set<Char> =
+ (this.polymer.toCharArray() + rules.map { it.a.toString() + it.b + it.input }
+ .joinToString(separator = "") { it }.toCharArray()).toSet()
+
+ fun Data.polymerization(steps: Int): String {
+ var polymer = this.polymer
+ for (i in 0 until steps) {
+ val array = CharArray(polymer.length * 2 - 1)
+ polymer.windowed(2).forEachIndexed { pos, value ->
+ array[pos * 2] = value[0]
+ array[pos * 2 + 1] = this.rules.first { value[0] == it.a && value[1] == it.b }.input
+ }
+ array[array.size - 1] = polymer.last()
+ polymer = array.concatToString()
+ }
+ return polymer
+ }
+
+
+ fun part1(data: Data): Int {
+ val grouped = data.polymerization(10).groupBy { it }
+ return grouped.maxOf { it.value.size } - grouped.minOf { it.value.size }
+ }
+
+ fun MutableMap<String, Long>.append(pair: String, times: Long = 1) {
+ this[pair] = (this[pair] ?: 0) + times
+ }
+
+ fun MutableMap<String, Long>.drop(pair: String, times: Long = 1) {
+ this[pair] = (this[pair] ?: 0) - times
+ }
+
+ fun part2(data: Data): Long {
+ val counts: MutableMap<String, Long> = mutableMapOf()
+ val countsPlus: MutableMap<String, Long> = mutableMapOf()
+
+ data.polymer.windowed(2).forEach { counts.append(it) }
+
+ // print("0: ")
+ // counts.forEach { (key, value) -> print("$key: $value, ") }
+ // println()
+
+ for (i in 0 until 40) {
+ counts.forEach { count ->
+ data.rules.first { it.a == count.key[0] && it.b == count.key[1] }.let { insertion ->
+ countsPlus.append(insertion.a.toString() + insertion.input.toString(), count.value)
+ countsPlus.append(insertion.input.toString() + insertion.b.toString(), count.value)
+ countsPlus.drop(count.key, count.value)
+ }
+ }
+ countsPlus.forEach { (key, value) -> counts[key] = (counts[key] ?: 0) + value }
+ countsPlus.clear()
+ counts.filter { it.value == 0L }.forEach { counts.remove(it.key) }
+ // print("${i + 1}: ")
+ // counts.forEach { (key, value) -> print("$key: $value, ") }
+ // println()
+ }
+
+ val result: MutableMap<Char, Long> = mutableMapOf()
+ data.allPosibilities().forEach {
+ result[it] = 0
+ }
+
+ counts.map { it.key[0] to it.value }.forEach { result[it.first] = (result[it.first] ?: 0) + it.second }
+ result[data.polymer.last()] = (result[data.polymer.last()] ?: 0) + 1
+
+ return result.maxOf { it.value } - result.minOf { it.value }
+ }
+
+ // ---- RUN
+
+ fun File.read(): Data {
+ var polymer = ""
+ val rules = mutableListOf<Insertion>()
+ readLines().forEachIndexed { id, value ->
+ when (id) {
+ 0 -> polymer = value
+ 1 -> {}
+ else -> rules.add(Insertion(value[0], value[1], value[6]))
+ }
+ }
+ rules.sortBy { it.a }
+ return Data(polymer, rules)
+ }
+
+ val testData = File(rootDir, "input_test.txt").read()
+ val data = File(rootDir, "input.txt").read()
+
+ verify(1588, part1(testData))
+ verify(3306, part1(data))
+
+ verify(2188189693529, part2(testData))
+ verify(3760312702877, part2(data))
+}

src/day14/input.txt

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

src/day14/input_test.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

src/dayXX/DayXX.kt

@@ -3,30 +3,29 @@ package dayXX
 import utils.verify
 import java.io.File
 
-/** https://adventofcode.com/2021/day/TODO */
+/** https://adventofcode.com/2021/day/XX */
 
 fun main() {
 
- fun part1(numbers: List<String>): Int {
- return TODO()
- }
-
+ val rootDir = File("src/dayXX/")
 
- fun part2(numbers: List<String>): Int {
- return TODO()
+ fun part1(data: List<String>): Int {
+ return -1
  }
 
- // ---- TEST
-
- val testNumbers = File("src/dayXX/input_test.txt").readLines()
 
- verify(TODO(), part1(testNumbers))
- verify(TODO(), part2(testNumbers))
+ fun part2(data: List<String>): Int {
+ return -1
+ }
 
  // ---- RUN
 
- val numbers = File("src/dayXX/input.txt").readLines()
+ val testData = File(rootDir, "input_test.txt").readLines()
+ val data = File(rootDir, "input.txt").readLines()
+
+ verify(0, part1(testData))
+ verify(0, part1(data))
 
- verify(TODO(), part1(numbers))
- verify(TODO(), part2(numbers))
+ verify(0, part2(testData))
+ verify(0, part2(data))
 }