Problem 34

src/main/scala/ninetyNineScalaProblems/arithmetic/Problem34.scala

@@ -0,0 +1,17 @@
+package ninetyNineScalaProblems.arithmetic
+
+import scala.annotation.tailrec
+
+object Problem34:
+    def totient(int: Int): Int =
+        @tailrec
+        def loop(cursor: Int, acc: Int): Int =
+            cursor match
+                case c if c == int =>
+                    acc
+                case c if Problem33.coprime(c, int) =>
+                    loop(cursor + 1, acc + 1)
+                case _ =>
+                    loop(cursor + 1, acc)
+
+        loop(0, 0)

src/test/scala/ninetyNineScalaProblems/arithmetic/Problem34Suite.scala

@@ -0,0 +1,14 @@
+package ninetyNineScalaProblems.arithmetic
+
+class Problem34Suite extends munit.FunSuite:
+    List(
+        (0, 0),
+        (1, 1),
+        (2, 1),
+        (3, 2),
+        (42, 12),
+        (10, 4),
+    ).foreach:
+        case (int, expected) =>
+            test(s"totient returns [$expected]"):
+                assertEquals(Problem34.totient(int), expected)