feat: 2025 day 06 source code

Author: scarf005

2025/project.scala

@@ -0,0 +1,3 @@
+//> using scala 3.7.4
+//> using option -Wunused:all
+//> using test.dep org.scalameta::munit::1.2.1

2025/src/day06.scala

@@ -0,0 +1,39 @@
+package day06
+
+import locations.Directory.currentDir
+import inputs.Input.loadFileSync
+
+@main def part1: Unit =
+  println(s"The solution is ${part1(loadInput())}")
+
+@main def part2: Unit =
+  println(s"The solution is ${part2(loadInput())}")
+
+def loadInput(): String = loadFileSync(s"$currentDir/../input/day06")
+
+extension [A](xs: IterableOnce[A])
+  inline def splitBy(sep: A) =
+    val (b, cur) = (Vector.newBuilder[Vector[A]], Vector.newBuilder[A])
+    for e <- xs.iterator do
+      if e != sep then cur += e else { b += cur.result(); cur.clear() }
+    (b += cur.result()).result()
+
+extension (xs: IterableOnce[(symbol: String, nums: IterableOnce[String])])
+  inline def calculate: Long = xs.iterator.collect {
+    case ("*", nums) => nums.iterator.map(_.toLong).product
+    case ("+", nums) => nums.iterator.map(_.toLong).sum
+  }.sum
+
+def part1(input: String): Long = input.linesIterator.toVector
+  .map(_.trim.split(raw"\s+"))
+  .transpose
+  .iterator
+  .map { col => (col.last, col.view.init) }
+  .calculate
+
+def part2(input: String): Long =
+  val lines = input.linesIterator.toVector
+  val ops = lines.last.split(raw"\s+").toVector
+  val xss = lines.init.transpose.map(_.mkString.trim).splitBy("")
+
+  (ops lazyZip xss).calculate

2025/src/inputs.scala

@@ -0,0 +1,9 @@
+package inputs
+
+import scala.util.Using
+import scala.io.Source
+
+object Input:
+
+  def loadFileSync(path: String): String =
+    Using.resource(Source.fromFile(path))(_.mkString)

2025/src/locations.scala

@@ -0,0 +1,19 @@
+package locations
+
+import scala.quoted.*
+
+object Directory:
+
+  /** The absolute path of the parent directory of the file that calls this method
+    * This is stable no matter which directory runs the program.
+    */
+  inline def currentDir: String = ${ parentDirImpl }
+
+  private def parentDirImpl(using Quotes): Expr[String] =
+    // position of the call to `currentDir` in the source code
+    val position = quotes.reflect.Position.ofMacroExpansion
+    // get the path of the file calling this macro
+    val srcFilePath = position.sourceFile.getJPath.get
+    // get the parent of the path, which is the directory containing the file
+    val parentDir = srcFilePath.getParent().toAbsolutePath
+    Expr(parentDir.toString) // convert the String to Expr[String]

README.md

@@ -9,6 +9,8 @@ See earlier editions:
 - [2021](/2021/README.md)
 - [2022](/2022/README.md)
 - [2023](/2023/README.md)
+- [2024](/2024/README.md)
+- [2025](/2025/README.md)
 
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