aoc-2024 - Day03

Author: Krystian Kaniowski

advent-of-code-2024/src/Day03.kt

@@ -0,0 +1,47 @@
+fun main() {
+
+ val pattern = "mul\\(\\d*,\\d*\\)".toRegex()
+
+ fun String.runProgram() = pattern.findAll(this)
+ .sumOf { finding ->
+ finding.value
+ .drop(4)
+ .dropLast(1)
+ .split(",")
+ .map { it.toInt() }
+ .let { it[0] * it[1] }
+ }
+
+ fun part1(input: List<String>): Int {
+
+ val result = input.sumOf { line -> line.runProgram() }
+
+ return result
+ }
+
+ fun part2(input: List<String>): Int {
+
+ val result = run {
+ val substrings = input.joinToString("").split("don't()")
+ var sum = 0
+ substrings.forEachIndexed { index, string ->
+ sum += when {
+ index == 0 -> string.runProgram()
+ else -> string.split("do()").drop(1).sumOf { it.runProgram() }
+ }
+ }
+ sum
+ }
+
+ return result
+ }
+
+ val testInput = readInput("Day03_test")
+ val test2Input = readInput("Day03_test2")
+ val input = readInput("Day03")
+
+ test(161) { part1(testInput) }
+ exec { part1(input) }
+ test(48) { part2(test2Input) }
+ exec { part2(input) }
+}