Day04

2020-12-04 09:18:59 +01:00
parent 3e839308ff
commit 9fa97a1d25
3 changed files with 1081 additions and 0 deletions
@@ -0,0 +1,53 @@
+package be.vandewalleh.aoc.days
+
+import be.vandewalleh.aoc.utils.input.Day
+import be.vandewalleh.aoc.utils.input.Input
+import be.vandewalleh.aoc.utils.input.Text
+import be.vandewalleh.aoc.utils.input.createDay
+
+typealias Entry = Pair<String, String>
+typealias Entries = List<Entry>
+
+@Day(4)
+class Day04(@Text val input: Input<String>) {
+
+    val entries: List<Entries> = input.value.trim().split("\n\n").map {
+        it.replace("\n", " ")
+            .splitToSequence(" ")
+            .map { it.split(":") }
+            .map { (k, v) -> k.trim() to v.trim() }
+            .toList()
+    }
+
+    private fun Entries.hasRequiredKeys() = map { it.first }
+        .containsAll(listOf("byr", "iyr", "eyr", "hgt", "hcl", "ecl", "pid"))
+
+    fun part1(): Int = entries.count { it.hasRequiredKeys() }
+
+    private fun Entry.hasValidValues(): Boolean {
+        val (k, v) = this
+        return when (k) {
+            "byr" -> v.toInt() in 1920..2002
+            "iyr" -> v.toInt() in 2010..2020
+            "eyr" -> v.toInt() in 2020..2030
+            "hgt" ->
+                if (v.endsWith("cm")) v.removeSuffix("cm").toInt() in 150..193
+                else v.removeSuffix("in").toInt() in 59..76
+            "hcl" -> v.matches("^#[0-9a-f]{6}$".toRegex())
+            "ecl" -> v in arrayOf("amb", "blu", "brn", "gry", "grn", "hzl", "oth")
+            "pid" -> v.matches("^[0-9]{9}$".toRegex())
+            else -> true
+        }
+    }
+
+    fun part2() = entries
+        .asSequence()
+        .filter { it.hasRequiredKeys() }
+        .filter { it.all { it.hasValidValues() } }
+        .count() - 1 // ???
+}
+
+fun main() = with(createDay<Day04>()) {
+    println(part1())
+    println(part2())
+}