solve 25th day 1st task

0legg · 0legg · commit 1bb09e56c6da · 2024-12-30T10:14:32.000-08:00
diff --git a/year2024/src/main/kotlin/net/olegg/aoc/year2024/day25/Day25.kt b/year2024/src/main/kotlin/net/olegg/aoc/year2024/day25/Day25.kt
@@ -0,0 +1,39 @@
+package net.olegg.aoc.year2024.day25
+
+import net.olegg.aoc.someday.SomeDay
+import net.olegg.aoc.utils.transpose
+import net.olegg.aoc.year2024.DayOf2024
+
+/**
+ * See [Year 2024, Day 25](https://adventofcode.com/2024/day/25)
+ */
+object Day25 : DayOf2024(25) {
+  override fun first(): Any? {
+    val rawSets = data.split("\n\n")
+    val (rawLocks, rawKeys) = rawSets.partition { it.startsWith("#") }
+
+    val locks = rawLocks.map { rawLock ->
+      rawLock.lines()
+        .map { it.toList() }
+        .transpose()
+        .map { column -> column.count { it == '#' } }
+    }
+
+    val keys = rawKeys.map { rawKey ->
+      rawKey.lines()
+        .map { it.toList() }
+        .transpose()
+        .map { column -> column.count { it == '#' } }
+    }
+
+    val size = rawLocks.first().lines().count()
+
+    return locks.sumOf { lock ->
+      keys.count { key ->
+        lock.zip(key).all { it.first + it.second <= size }
+      }
+    }
+  }
+}
+
+fun main() = SomeDay.mainify(Day25)
