Problem 11

src/main/scala/ninetyNineScalaProblems/Problem11.scala

@@ -0,0 +1,17 @@
+package ninetyNineScalaProblems
+
+import scala.annotation.tailrec
+
+object Problem11:
+    def modifiedRunLengthEncode(list: List[Any]): List[Tuple2[Int, Any] | Any] =
+        @tailrec
+        def loop(cursor: List[Tuple2[Int, Any]], acc: List[Tuple2[Int, Any] | Any]): List[Tuple2[Int, Any] | Any] =
+            cursor match
+                case d :: tail if d._1 > 1 =>
+                    loop(tail, (d._1, d._2) :: acc)
+                case d :: tail =>
+                    loop(tail, d._2 :: acc)
+                case Nil =>
+                    acc
+
+        loop(Problem10.runLengthEncode(list), List()).reverse

src/test/scala/ninetyNineScalaProblems/Problem11Suite.scala

@@ -0,0 +1,17 @@
+package ninetyNineScalaProblems
+
+import scala.compiletime.ops.boolean
+
+class Problem11Suite extends munit.FunSuite:
+    List(
+        (List(1, 2, 3, 4), List(1, 2, 3, 4)),
+        (List(1, 2, 2, 3), List(1, (2, 2), 3)),
+        (List(1, 2, 3, 2), List(1, 2, 3, 2)),
+        (List(), List()),
+        (List(1), List(1)),
+        (List(1, 1), List((2, 1))),
+        (List(1, 1, 1, 1, 2, 3, 3, 1, 1, 4, 5, 5, 5, 5), List((4, 1), 2, (2, 3), (2, 1), 4, (4, 5)))
+    ).foreach:
+        case (list, expected) =>
+            test(s"modifiedRunLengthEncode returns [$expected]"):
+                assertEquals(Problem11.modifiedRunLengthEncode(list), expected)