From 4cb7b4e95b47d00b4a3f91c11127e607cde9d237 Mon Sep 17 00:00:00 2001
From: Jakob Scheid <jakob.scheid@icloud.com>
Date: Thu, 19 Mar 2026 15:39:35 +0100
Subject: [PATCH] Problem 18

---
 .../ninetyNineScalaProblems/Problem18.scala    | 17 +++++++++++++++++
 .../Problem18Suite.scala                       | 18 ++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 src/main/scala/ninetyNineScalaProblems/Problem18.scala
 create mode 100644 src/test/scala/ninetyNineScalaProblems/Problem18Suite.scala

diff --git a/src/main/scala/ninetyNineScalaProblems/Problem18.scala b/src/main/scala/ninetyNineScalaProblems/Problem18.scala
new file mode 100644
index 0000000..ab01a59
--- /dev/null
+++ b/src/main/scala/ninetyNineScalaProblems/Problem18.scala
@@ -0,0 +1,17 @@
+package ninetyNineScalaProblems
+
+import scala.annotation.tailrec
+
+object Problem18:
+    def slice(i: Int, k: Int, list: List[Any]): List[Any] =
+        @tailrec
+        def loop(cursor: List[Any], acc: List[Any], index: Int): List[Any] =
+            cursor match
+                case e :: tail if (i <= index && index < k) =>
+                    loop(tail, e :: acc, index + 1)
+                case e :: tail =>
+                    loop(tail, acc, index + 1)
+                case Nil =>
+                    acc
+
+        loop(list, List(), 0).reverse
\ No newline at end of file
diff --git a/src/test/scala/ninetyNineScalaProblems/Problem18Suite.scala b/src/test/scala/ninetyNineScalaProblems/Problem18Suite.scala
new file mode 100644
index 0000000..d7ec305
--- /dev/null
+++ b/src/test/scala/ninetyNineScalaProblems/Problem18Suite.scala
@@ -0,0 +1,18 @@
+package ninetyNineScalaProblems
+
+import scala.compiletime.ops.boolean
+
+class Problem18Suite extends munit.FunSuite:
+    List(
+        ((0, 0, List(1, 2, 3, 4)), List()),
+        ((0, 1, List(1, 2, 3, 4)), List(1)),
+        ((1, 1, List(1, 2, 3, 4)), List()),
+        ((1, 2, List(1, 2, 3, 4)), List(2)),
+        ((1, 3, List(1, 2, 3, 4)), List(2, 3)),
+        ((1, 4, List(1, 2, 3, 4)), List(2, 3, 4)),
+        ((1, 5, List(1, 2, 3, 4)), List(2, 3, 4)),
+        ((1, 0, List(1, 2, 3, 4)), List()),
+    ).foreach:
+        case ((i, k, list), expected) =>
+            test(s"slice returns [$expected]"):
+                assertEquals(Problem18.slice(i, k, list), expected)
\ No newline at end of file