added ex4

tests/test_ex4.py

@@ -1,8 +1,21 @@
 import unittest
 
+from Ex4 import computeNbrOfDifferentSequences
+
+
 class MyTestCase(unittest.TestCase):
     def test_simple1(self):
-        pass
+        self.assertEqual(
+            computeNbrOfDifferentSequences(1, 6, 3),
+            1
+        )
+
+    def test_simple2(self):
+        self.assertEqual(
+            computeNbrOfDifferentSequences(2, 6, 7),
+            6
+        )
+
 
 if __name__ == '__main__':
     unittest.main()