Solved day09 part 1

Author: Gentleman1983

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2023'
-version '0.8.2'
+version '0.8.3'
 
 // Switch to gradle "all" distribution.
 wrapper {

day09/src/main/kotlin/de/havox_design/aoc2023/day09/Day09.kt

@@ -2,11 +2,38 @@ package de.havox_design.aoc2023.day09
 
 class Day09(private var filename: String) {
     fun solvePart1(): Long =
-        0L
+        convertInput()
+            .sumOf { history ->
+            processOasisReport(history)
+        }
 
     fun solvePart2(): Long =
         0L
 
+    private fun processOasisReport(oasisHistory: List<Long>): Long {
+        var value = 0L
+        var factor = 1
+        var current = oasisHistory
+
+        while (current.any { it != 0L }) {
+            value += current.last()
+
+            current = current.windowed(2).map { (a, b) -> b - a }
+        }
+
+        return value
+    }
+
+    private fun convertInput(): List<List<Long>> =
+        getResourceAsText(filename)
+            .map { row ->
+                row
+                    .split(" ")
+                    .stream()
+                    .map { element -> element.toLong() }
+                    .toList()
+            }
+
     private fun getResourceAsText(path: String): List<String> =
         this.javaClass.classLoader.getResourceAsStream(path)!!.bufferedReader().readLines()
 }

day09/src/test/kotlin/de/havox_design/aoc2023/day09/Day09Test.kt

@@ -27,10 +27,10 @@ class Day09Test {
         @JvmStatic
         private fun getDataForTestSolvePart1(): Stream<Arguments> =
             Stream.of(
-                Arguments.of("part1sample1.txt", 0L),
-                Arguments.of("part1sample2.txt", 0L),
-                Arguments.of("part1sample3.txt", 0L),
-                Arguments.of("part1sample4.txt", 0L)
+                Arguments.of("part1sample1.txt", 18L),
+                Arguments.of("part1sample2.txt", 28L),
+                Arguments.of("part1sample3.txt", 68L),
+                Arguments.of("part1sample4.txt", 114L)
             )
 
         @JvmStatic