Day06

days/src/main/kotlin/Day06.kt

@@ -0,0 +1,32 @@
+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
+import org.eclipse.collections.impl.factory.primitive.CharBags
+
+@Day(6)
+class Day06(@Text val input: Input<String>) {
+
+    private val groups = input.value.split("\n\n")
+
+    fun part1(): Int = groups.map { it.replace("\\s+".toRegex(), "") }
+        .map { it.toCharArray().toSet() }
+        .map { it.size }.sum()
+
+    fun part2(): Int = groups.map {
+        val group = it.split("\n").map { it.trim() }
+        val bag = CharBags.mutable.empty()
+        group.forEach { chars: String -> chars.forEach { bag.add(it) } }
+        bag.selectByOccurrences { group.size == it }
+            .selectUnique()
+            .size()
+    }.sum()
+
+}
+
+fun main() = with(createDay<Day06>()) {
+    println(part1())
+    println(part2())
+}