Problem 18

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

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)