2024 Day 03 Part 2

fmmr · Dec 3, 2024 · 9d93c33 · 9d93c33
1 parent d26212b
commit 9d93c33
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Showing 3 changed files with 32 additions and 14 deletions.
diff --git a/src/main/kotlin/no/rodland/advent_2024/Day03.kt b/src/main/kotlin/no/rodland/advent_2024/Day03.kt
@@ -5,26 +5,44 @@ import no.rodland.advent.Day
 // template generated: 03/12/2024
 // Fredrik Rødland 2024
 
-class Day03(val input: List<String>) : Day<Long, Long, List<Pair<Int, Int>>> {
-    private val multRegEx = "mul\\((\\d{1,3}),(\\d{1,3})\\)".toRegex()
+class Day03(val input: List<String>) : Day<Long, Long, List<String>> {
+    private val multRegEx = """mul\((\d{1,3}),(\d{1,3})\)""".toRegex()
 
     private val parsed = input.parse()
 
     override fun partOne(): Long {
-        return parsed.sumOf { (a, b) -> a * b }.toLong()
+        return parsed
+            .flatMap { line ->
+                multRegEx.findAll(line).toList().map { mr ->
+                    mr.groupValues[1].toInt() * mr.groupValues[2].toInt()
+                }
+            }
+            .sum()
+            .toLong()
     }
 
     override fun partTwo(): Long {
-        return 2
-    }
-
-    override fun List<String>.parse(): List<Pair<Int, Int>> {
-        return flatMap { line ->
-            multRegEx.findAll(line).toList().map { mr ->
-                mr.groupValues[1].toInt() to mr.groupValues[2].toInt()
+        val matches = """mul\((\d{1,3}),(\d{1,3})\)|do\(\)|don't\(\)""".toRegex()
+        var inDoMode = true
+        return parsed
+            .flatMap { line ->
+                sequence {
+                    matches
+                        .findAll(line)
+                        .forEach { mr ->
+                            when {
+                                mr.value == "do()" -> inDoMode = true
+                                mr.value == "don't()" -> inDoMode = false
+                                multRegEx.matches(mr.value) && inDoMode -> yield(mr.groupValues[1].toInt() * mr.groupValues[2].toInt())
+                            }
+                        }
+                }
             }
-        }
+            .sum()
+            .toLong()
     }
 
+    override fun List<String>.parse(): List<String> = this
+
     override val day = "03".toInt()
 }
diff --git a/src/test/kotlin/no/rodland/advent_2024/Day03Test.kt b/src/test/kotlin/no/rodland/advent_2024/Day03Test.kt
@@ -16,9 +16,9 @@ internal class Day03Test {
     private val test03 = "2024/input_03_test.txt".readFile()
 
     private val resultTestOne = 161L
-    private val resultTestTwo = 2L
+    private val resultTestTwo = 48L
     private val resultOne = 187825547L
-    private val resultTwo = 2L
+    private val resultTwo = 85508223L
 
     val test = defaultTestSuiteParseOnInit(
         Day03(data03),

diff --git a/src/test/resources/2024/input_03_test.txt b/src/test/resources/2024/input_03_test.txt
@@ -1 +1 @@
-xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
+xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
		xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))