Add day 9 dummy

Author: michaeltroger

src/Day8.kt

@@ -8,7 +8,7 @@ fun main() {
 
     fun part2(input: List<String>): Int {
         var sum = 0
-        
+
         val parsedInput = input.map {
             it.split(" | ").map { it.split(" ") }
         }
@@ -90,5 +90,4 @@ fun main() {
     println(part2(input))
 }
 
-private fun String.sortAlphabetically() = toCharArray().sorted().joinToString("")
-
+private fun String.sortAlphabetically() = toCharArray().sorted().joinToString("")

src/Day9.kt

@@ -0,0 +1,15 @@
+private const val DAY = 9
+
+fun main() {
+    fun part1(input: List<String>) =-1
+    fun part2(input: List<String>) = -1
+
+    // test if implementation meets criteria from the description, like:
+    val testInput = readInput(day = DAY, useTestInput = true)
+    check(part1(testInput) == 15)
+    check(part2(testInput) == 61229)
+
+    val input = readInput(day = DAY)
+    println(part1(input))
+    println(part2(input))
+}