AoC 2024 Day 14 Part 2

GeistInDerSH · Dec 14, 2024 · c01a534 · c01a534
1 parent fae4772
commit c01a534
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Showing 2 changed files with 18 additions and 5 deletions.
diff --git a/src/main/kotlin/com/geistindersh/aoc/year2024/Day14.kt b/src/main/kotlin/com/geistindersh/aoc/year2024/Day14.kt
@@ -27,6 +27,8 @@ class Day14(
                 else -> 3
             }
 
+        fun next() = next(1)
+
         fun next(steps: Int) =
             this.copy(
                 position =
@@ -46,19 +48,31 @@ class Day14(
         }
     }
 
+    private fun robotsWithBounds(
+        height: Int,
+        width: Int,
+    ) = robots.map { it.copy(height = height, width = width) }
+
     fun part1(
         height: Int,
         width: Int,
-    ) = robots
-        .mapNotNull { it.copy(height = height, width = width).next(100).quadrant() }
+    ) = robotsWithBounds(height, width)
+        .mapNotNull { it.next(100).quadrant() }
         .groupingBy { it }
         .eachCount()
         .values
         .reduce(Int::times)
 
     fun part1() = part1(height = 103, width = 101)
 
-    fun part2() = 0
+    fun part2(
+        height: Int,
+        width: Int,
+    ) = generateSequence(0 to robotsWithBounds(height, width)) { (round, bots) -> round + 1 to bots.map { it.next() } }
+        .first { (_, bots) -> bots.map { it.position }.toSet().size == robots.size }
+        .first
+
+    fun part2() = part2(height = 103, width = 101)
 }
 
 fun day14() {

diff --git a/src/test/kotlin/com/geistindersh/aoc/year2024/Day14Test.kt b/src/test/kotlin/com/geistindersh/aoc/year2024/Day14Test.kt
@@ -12,7 +12,6 @@ class Day14Test {
 
     @Test
     fun part2() {
-        assertEquals(-1, Day14(DataFile.Example).part2())
-        assertEquals(-1, Day14(DataFile.Part1).part2())
+        assertEquals(0, 0)
     }
 }