Solved day10 part 1

Author: Gentleman1983

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2023'
-version '0.9.1'
+version '0.9.2'
 
 // Switch to gradle "all" distribution.
 wrapper {

day10/src/main/kotlin/de/havox_design/aoc2023/day10/Day10.kt

@@ -1,12 +1,111 @@
 package de.havox_design.aoc2023.day10
 
 class Day10(private var filename: String) {
+    private val ICON_START = 'S'
+    private val ICON_VERTICAL_PIPE = '|'
+    private val ICON_HORIZONTAL_PIPE = '-'
+    private val ICON_NORTH_EAST_BEND = 'L'
+    private val ICON_NORTH_WEST_BEND = 'J'
+    private val ICON_SOUTH_WEST_BEND = '7'
+    private val ICON_SOUTH_EAST_BEND = 'F'
+    private val ICON_FREE_GROUND = '.'
+
     fun solvePart1(): Long =
-        0L
+        solvePart1(
+            getResourceAsText(filename)
+                .map { row -> row.toCharArray().toList() }
+        )
 
     fun solvePart2(): Long =
         0L
 
+    private fun solvePart1(maze: List<List<Char>>): Long {
+        var start: Pair<Int, Int>? = null
+
+        out@ for (row in maze.indices) {
+            for (col in maze[row].indices) {
+                if (maze[row][col] == ICON_START) {
+                    start = Pair(row, col)
+                    break@out
+                }
+            }
+        }
+
+        val loop = getLoop(start!!, maze)
+
+        return (loop.size / 2).toLong()
+    }
+
+    private fun getLoop(start: Pair<Int, Int>, maze: List<List<Char>>): List<Pair<Int, Int>> {
+        val loop = mutableListOf(start)
+
+        do {
+            val adjacentCells = maze
+                .connectedCells(loop.last())
+                .filter { !loop.contains(it) }
+                .take(1)
+
+            loop.addAll(adjacentCells)
+        } while (adjacentCells.isNotEmpty())
+
+        return loop
+    }
+
+    private fun List<List<Char>>.connectedCells(currentLocation: Pair<Int, Int>): List<Pair<Int, Int>> {
+        return when (this[currentLocation.first][currentLocation.second]) {
+            ICON_VERTICAL_PIPE -> listOf(
+                currentLocation.getAdjacentField(Direction.NORTH),
+                currentLocation.getAdjacentField(Direction.SOUTH)
+            )
+
+            ICON_HORIZONTAL_PIPE -> listOf(
+                currentLocation.getAdjacentField(Direction.WEST),
+                currentLocation.getAdjacentField(Direction.EAST)
+            )
+
+            ICON_NORTH_EAST_BEND -> listOf(
+                currentLocation.getAdjacentField(Direction.NORTH),
+                currentLocation.getAdjacentField(Direction.EAST)
+            )
+
+            ICON_NORTH_WEST_BEND -> listOf(
+                currentLocation.getAdjacentField(Direction.NORTH),
+                currentLocation.getAdjacentField(Direction.WEST)
+            )
+
+            ICON_SOUTH_WEST_BEND -> listOf(
+                currentLocation.getAdjacentField(Direction.WEST),
+                currentLocation.getAdjacentField(Direction.SOUTH)
+            )
+
+            ICON_SOUTH_EAST_BEND -> listOf(
+                currentLocation.getAdjacentField(Direction.EAST),
+                currentLocation.getAdjacentField(Direction.SOUTH)
+            )
+
+            ICON_START -> listOf(
+                currentLocation.getAdjacentField(Direction.NORTH),
+                currentLocation.getAdjacentField(Direction.WEST),
+                currentLocation.getAdjacentField(Direction.EAST),
+                currentLocation.getAdjacentField(Direction.SOUTH)
+            )
+                .filter { (it.first in indices) && (it.second in this[it.first].indices) }
+                .filter { this.connectedCells(it).any { next -> next == currentLocation } }
+
+            else -> emptyList()
+        }.filter { (it.first in indices) && (it.second in this[it.first].indices) }
+    }
+
+    private fun Pair<Int, Int>.getAdjacentField(direction: Direction): Pair<Int, Int> {
+        return when (direction) {
+            Direction.NORTH -> Pair(this.first - 1, this.second)
+            Direction.SOUTH -> Pair(this.first + 1, this.second)
+            Direction.WEST -> Pair(this.first, this.second - 1)
+            Direction.EAST -> Pair(this.first, this.second + 1)
+            Direction.NONE -> this
+        }
+    }
+
     private fun getResourceAsText(path: String): List<String> =
         this.javaClass.classLoader.getResourceAsStream(path)!!.bufferedReader().readLines()
 }

day10/src/main/kotlin/de/havox_design/aoc2023/day10/Direction.kt

@@ -0,0 +1,9 @@
+package de.havox_design.aoc2023.day10
+
+enum class Direction {
+    NORTH,
+    SOUTH,
+    WEST,
+    EAST,
+    NONE
+}

day10/src/test/kotlin/de/havox_design/aoc2023/day10/Day10Test.kt

@@ -27,8 +27,8 @@ class Day10Test {
         @JvmStatic
         private fun getDataForTestSolvePart1(): Stream<Arguments> =
             Stream.of(
-                Arguments.of("part1sample1.txt", 0L),
-                Arguments.of("part1sample2.txt", 0L)
+                Arguments.of("part1sample1.txt", 4L),
+                Arguments.of("part1sample2.txt", 8L)
             )
 
         @JvmStatic