Day02 2021

2021/src/main/kotlin/Day02.kt

@@ -0,0 +1,40 @@
+package be.vandewalleh.aoc.days
+
+import be.vandewalleh.aoc.utils.input.Day
+import be.vandewalleh.aoc.utils.input.Text
+
+@Day
+class Day02(@Text input: String) {
+    private val lines = input.lines().map { it.split(' ').let { it[0] to it[1].toInt() } }
+
+    fun part1(): Any {
+        var horizontalPosition = 0
+        var depth = 0
+        lines.forEach { (direction, value) ->
+                when (direction) {
+                    "forward" -> horizontalPosition += value
+                    "down" -> depth += value
+                    "up" -> depth -= value
+                }
+            }
+        return horizontalPosition * depth
+    }
+
+    fun part2(): Any {
+        var horizontalPosition = 0
+        var depth = 0
+        var aim = 0
+        lines.forEach { (direction, value) ->
+                when (direction) {
+                    "forward" -> {
+                        horizontalPosition += value
+                        depth += aim * value
+                    }
+                    "down" -> aim += value
+                    "up" -> aim -= value
+                }
+            }
+        return horizontalPosition * depth
+    }
+
+}

2021/src/test/kotlin/Day02Test.kt

@@ -0,0 +1,18 @@
+package be.vandewalleh.aoc.days
+
+class Day02Test : BaseDayTest(2) {
+    override val example = """
+        forward 5
+        down 5
+        forward 8
+        up 3
+        down 8
+        forward 2
+    """.trimIndent()
+
+    override val part1Example = 150
+    override val part2Example = 900
+
+    override val part1Answer = 1938402
+    override val part2Answer = 1947878632
+}