Move year 2021 into a subfolder

1 files changed, 24 insertions, 0 deletions

diff --git a/2021-kotlin/src/Day01.kt b/2021-kotlin/src/Day01.kt
new file mode 100644
index 0000000..4ac1ef7
--- /dev/null
+++ b/2021-kotlin/src/Day01.kt
@@ -0,0 +1,24 @@
+object Day01 {
+    fun part1(input: List<Int>) =
+        input
+            .zipWithNext()
+            .count { it.second > it.first }
+
+    fun part2(input: List<Int>) =
+        input
+            .asSequence()
+            .windowed(3)
+            .map { it.sum() }
+            .zipWithNext()
+            .count { it.second > it.first }
+}
+
+fun main() {
+    val testInput = readInputAsNumbers("Day01_test")
+    check(Day01.part1(testInput) == 7)
+    check(Day01.part2(testInput) == 5)
+
+    val input = readInputAsNumbers("Day01")
+    println(Day01.part1(input))
+    println(Day01.part2(input))
+}