Just another update

Task/Order-two-numerical-lists/Scala/order-two-numerical-lists-1.scala

@@ -0,0 +1,5 @@
+def lessThan1(a: List[Int], b: List[Int]): Boolean =
+  if (b.isEmpty) false
+  else if (a.isEmpty) true
+  else if (a.head != b.head) a.head < b.head
+  else lessThan1(a.tail, b.tail)

Task/Order-two-numerical-lists/Scala/order-two-numerical-lists-2.scala

@@ -0,0 +1,6 @@
+def lessThan2(a: List[Int], b: List[Int]): Boolean = (a, b) match {
+  case (_, Nil) => false
+  case (Nil, _) => true
+  case (a :: _, b :: _) if a != b => a < b
+  case _ => lessThan2(a.tail, b.tail)
+}

Task/Order-two-numerical-lists/Scala/order-two-numerical-lists-3.scala

@@ -0,0 +1,5 @@
+def lessThan3(a: List[Int], b: List[Int]): Boolean =
+  a.zipAll(b, Integer.MIN_VALUE, Integer.MIN_VALUE)
+   .find{case (a, b) => a != b}
+   .map{case (a, b) => a < b}
+   .getOrElse(false)

Task/Order-two-numerical-lists/Scala/order-two-numerical-lists-4.scala

@@ -0,0 +1,14 @@
+val tests = List(
+  (List(1, 2, 3), List(1, 2, 3)) -> false,
+  (List(3, 2, 1), List(3, 2, 1)) -> false,
+  (List(1, 2, 3), List(3, 2, 1)) -> true,
+  (List(3, 2, 1), List(1, 2, 3)) -> false,
+  (List(1, 2), List(1, 2, 3)) -> true,
+  (List(1, 2, 3), List(1, 2)) -> false
+)
+
+tests.foreach{case test @ ((a, b), c) =>
+  assert(lessThan1(a, b) == c, test)
+  assert(lessThan2(a, b) == c, test)
+  assert(lessThan3(a, b) == c, test)
+}