diff --git a/README.md b/README.md
index a9f4073..e967055 100644
--- a/README.md
+++ b/README.md
@@ -5,11 +5,11 @@ This repo contains my attempt at this year's Advent of Code (2023)
I will try and do some problems (probably not all of them) in Scala
## Progress:
-#### Stars: 23 / 50
-| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
-|:------------------:|:-----------------:|:-----------------:|:-----------------:|:-----------------:|:-----------------:|:------------------:|
-| | | | | 1
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-| 4
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-| 11
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-| 18 | 19 | 20 | 21 | 22 | 23 | 24 |
-| 25 | | | | | | |
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+#### Stars: 24 / 50
+| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
+|:------------------:|:-----------------:|:------------------:|:-----------------:|:-----------------:|:-----------------:|:------------------:|
+| | | | | 1
:star::star: | 2
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+| 4
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+| 11
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+| 18 | 19 | 20 | 21 | 22 | 23 | 24 |
+| 25 | | | | | | |
\ No newline at end of file
diff --git a/src/day13/Puzzle2.scala b/src/day13/Puzzle2.scala
new file mode 100644
index 0000000..d39e1b6
--- /dev/null
+++ b/src/day13/Puzzle2.scala
@@ -0,0 +1,94 @@
+package day13
+
+import scala.io.{BufferedSource, Source}
+
+object Puzzle2 {
+ var maps: Array[Array[Array[Boolean]]] = Array.empty
+ def loadInput(path: String): Unit = {
+ val source: BufferedSource = Source.fromFile(path)
+ val lines: String = source.getLines().mkString("\n")
+
+ val mapsStr: Array[String] = lines.split("\n\n")
+ maps = new Array(mapsStr.length)
+
+ for ((mapStr: String, i: Int) <- mapsStr.zipWithIndex) {
+ val rows: Array[String] = mapStr.split("\n")
+ val map: Array[Array[Boolean]] = new Array(rows.length)
+ for ((row: String, j: Int) <- rows.zipWithIndex) {
+ map(j) = row.map(_ == '#').toArray
+ }
+ maps(i) = map
+ }
+
+ source.close()
+ }
+
+ def getReflectionValue(map: Array[Array[Boolean]]): Int = {
+ val height: Int = map.length
+ val width: Int = if (height == 0) 0 else map(0).length
+ var value: Int = 0
+
+ for (x: Int <- 0 until width-1) {
+ if (isReflection(map, x)) {
+ value += x+1
+ }
+ }
+
+ val mapT: Array[Array[Boolean]] = transpose(map)
+
+ for (y: Int <- 0 until height-1) {
+ if (isReflection(mapT, y)) {
+ value += 100*(y+1)
+ }
+ }
+
+ return value
+ }
+
+ def isReflection(map: Array[Array[Boolean]], x: Int): Boolean = {
+ var diffs: Int = 0
+ for (row: Array[Boolean] <- map) {
+ val a = row.dropRight(row.length - x - 1).reverse
+ val b = row.drop(x+1)
+ for (i: Int <- 0 until Math.min(a.length, b.length)) {
+ if (a(i) != b(i)) {
+ diffs += 1
+ if (diffs > 1) return false
+ }
+ }
+ }
+ return diffs == 1
+ }
+
+ def transpose(map: Array[Array[Boolean]]): Array[Array[Boolean]] = {
+ val height: Int = map.length
+ val width: Int = if (height == 0) 0 else map(0).length
+
+ val mapT: Array[Array[Boolean]] = Array.ofDim(width, height)
+
+ for (y: Int <- 0 until height) {
+ for (x: Int <- 0 until width) {
+ mapT(x)(y) = map(y)(x)
+ }
+ }
+
+ return mapT
+ }
+
+ def solve(path: String): Int = {
+ loadInput(path)
+
+ var solution: Int = 0
+
+ for (map: Array[Array[Boolean]] <- maps) {
+ solution += getReflectionValue(map)
+ }
+
+ return solution
+ }
+
+ def main(args: Array[String]): Unit = {
+ val solution: Int = solve("./res/day13/input1.txt")
+ println(solution)
+ }
+}
diff --git a/tests/day13/Puzzle2Test.scala b/tests/day13/Puzzle2Test.scala
new file mode 100644
index 0000000..f77240c
--- /dev/null
+++ b/tests/day13/Puzzle2Test.scala
@@ -0,0 +1,9 @@
+package day13
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class Puzzle2Test extends AnyFunSuite {
+ test("Puzzle2.solve") {
+ assert(Puzzle2.solve("tests_res/day13/input1.txt") == 400)
+ }
+}