From 23e3b517e9611b318c32e6d1ded56c93c9faedb6 Mon Sep 17 00:00:00 2001
From: Hubert Van De Walle <hubv@protonmail.com>
Date: Sat, 5 Dec 2020 08:07:41 +0100
Subject: [PATCH] Mmh

---
 days/src/main/kotlin/Day05.kt | 46 ++++++++++-------------------------
 1 file changed, 13 insertions(+), 33 deletions(-)

diff --git a/days/src/main/kotlin/Day05.kt b/days/src/main/kotlin/Day05.kt
index 8782a0c..6f24c05 100644
--- a/days/src/main/kotlin/Day05.kt
+++ b/days/src/main/kotlin/Day05.kt
@@ -4,44 +4,24 @@ import be.vandewalleh.aoc.utils.input.Day
 import be.vandewalleh.aoc.utils.input.Input
 import be.vandewalleh.aoc.utils.input.Lines
 import be.vandewalleh.aoc.utils.input.createDay
-import kotlin.math.abs
 
 @Day(5)
 class Day05(@Lines val input: Input<List<String>>) {
 
-    private fun row(line: String) = line.take(7)
-        .replace("F", "0")
-        .replace("B", "1")
-        .let { Integer.parseInt(it, 2) }
-
-    private fun col(line: String) = line.takeLast(3)
-        .replace("L", "0")
-        .replace("R", "1")
-        .let { Integer.parseInt(it, 2) }
-
-    private fun id(seat: Pair<Int, Int>) = seat.first.times(8) + seat.second
-
-    fun part1() = input.value
-        .map { row(it) to col(it) }
-        .map { id(it) }
-        .maxOrNull()!!
-
-    fun part2(): Int {
-        val seats = input.value.map { row(it) to col(it) }
-
-        val front = seats.minByOrNull { it.first }!!.first
-        val back = seats.maxByOrNull { it.first }!!.first
-
-        return seats
-            .asSequence()
-            .filterNot { it.first == front }
-            .filterNot { it.first == back }
-            .map { id(it) }
-            .sorted()
-            .windowed(size = 2, step = 1)
-            .find { (a, b) -> abs(a - b) > 1 }!!
-            .first() + 1
+    private val ids = input.value.map {
+        it.replace("F", "0")
+            .replace("B", "1")
+            .replace("L", "0")
+            .replace("R", "1")
+            .toInt(2)
     }
+
+    fun part1() = ids.maxOrNull()
+
+    fun part2() = ids.sorted()
+        .windowed(size = 2, step = 1)
+        .find { (a, b) -> b - a > 1 }!!
+        .first() + 1
 }
 
 fun main() = with(createDay<Day05>()) {