From 47f865d9aa175fae0937c5e467893706e9d05093 Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Sat, 4 Dec 2021 15:57:28 +0100
Subject: [PATCH] day(03): refactor

Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 src/day03/Day03.kt | 90 +++++++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 49 deletions(-)

diff --git a/src/day03/Day03.kt b/src/day03/Day03.kt
index 5584b30..2edeedd 100644
--- a/src/day03/Day03.kt
+++ b/src/day03/Day03.kt
@@ -2,56 +2,48 @@ package day03
 
 import readInput
 
+fun toBits(input: List<String>): List<List<Int>> = input.map { row ->
+    row.map { if (it == '1') 1 else 0 }
+}
+
+fun part1(input: List<List<Int>>): Int {
+    var gamma = 0
+    var epsilon = 0
+
+    for (i in input[0].indices) {
+        gamma = gamma.shl(1)
+        epsilon = epsilon.shl(1)
+
+        val ones = input.indices.sumOf { input[it][i] }
+        if (2 * ones > input.size) gamma++ else epsilon++
+    }
+
+    return epsilon * gamma
+}
+
+fun part2(input: List<List<Int>>): Int {
+    fun part2Helper(predicate: (Int, Int) -> Boolean): Int {
+        var wanted = input.indices.toList()
+        var i = 0
+
+        while (wanted.size > 1) {
+            val ones = wanted.sumOf { input[it][i] }
+            val wantedBit = if (predicate(ones, wanted.size)) 1 else 0
+
+            wanted = wanted.filter { input[it][i] == wantedBit }.toList()
+            i++
+        }
+
+        return input[wanted[0]].fold(0) { n, d -> 2 * n + d }
+    }
+
+    val oxygenGeneratorRating = part2Helper { ones, length -> 2 * ones >= length }
+    val co2ScrubberRating = part2Helper { ones, length -> 2 * ones < length }
+
+    return oxygenGeneratorRating * co2ScrubberRating
+}
+
 fun main() {
-    fun toBits(input: List<String>): List<List<Int>> {
-        return input.map { row ->
-            row.map { if (it == '1') 1 else 0 }
-        }
-    }
-
-    fun part1(input: List<List<Int>>): Int {
-        var gamma = 0
-        var epsilon = 0
-
-        for (i in input[0].indices) {
-            gamma = gamma.shl(1)
-            epsilon = epsilon.shl(1)
-
-            val ones = input.indices.map { input[it][i] }.sum()
-
-            if (2 * ones > input.size) {
-                gamma++
-            } else {
-                epsilon++
-            }
-        }
-
-        return epsilon * gamma
-    }
-
-    fun part2(input: List<List<Int>>): Int {
-        fun part2Helper(predicate: (Int, Int) -> Boolean): Int {
-            var wanted = input.indices.toList()
-            var i = 0
-
-            while (wanted.size > 1) {
-                val ones = wanted.sumOf { input[it][i] }
-                val wantedBit = if (predicate(ones, wanted.size)) 1 else 0
-
-                wanted = wanted.filter { input[it][i] == wantedBit }.toList()
-                i++
-            }
-
-            return input[wanted[0]].fold(0) { n, d -> 2 * n + d }
-        }
-
-        val oxygenGeneratorRating = part2Helper { ones, length -> 2 * ones >= length }
-        val co2ScrubberRating = part2Helper { ones, length -> 2 * ones < length }
-
-        return oxygenGeneratorRating * co2ScrubberRating
-    }
-
-
     val testInput = toBits(readInput(3, "test_input"))
     val input = toBits(readInput(3, "input"))