finding number of digits using logs created with unit tests

vicky1999 · web-flow · commit 2dbf296f558b · 2020-11-17T18:56:44.000Z
diff --git a/.gitignore b/.gitignore
@@ -13,5 +13,5 @@ __pycache__/
 /*.egg
 # docs
 build/
-
+pythonenv3.8/
 .vscode/
diff --git a/algorithms/maths/__init__.py b/algorithms/maths/__init__.py
@@ -18,3 +18,4 @@
 from .find_order_simple import *
 from .find_primitive_root_simple import *
 from .diffie_hellman_key_exchange import *
+from .num_digits import *
diff --git a/algorithms/maths/num_digits.py b/algorithms/maths/num_digits.py
@@ -0,0 +1,10 @@
+"""
+   num_digits() method will return the number of digits of a number in O(1) time using math.log10() method.
+"""
+
+import math
+
+def num_digits(n):
+  if(n==0):
+      return 1;
+  return int(math.log10(n))+1
diff --git a/tests/test_maths.py b/tests/test_maths.py
@@ -19,7 +19,8 @@
     cosine_similarity,
     find_order,
     find_primitive_root,
-    alice_private_key, alice_public_key, bob_private_key, bob_public_key, alice_shared_key, bob_shared_key, diffie_hellman_key_exchange
+    alice_private_key, alice_public_key, bob_private_key, bob_public_key, alice_shared_key, bob_shared_key, diffie_hellman_key_exchange,
+    num_digits
 )
 
 import unittest
@@ -369,6 +370,18 @@ def test_find_order_simple(self):
         self.assertFalse(diffie_hellman_key_exchange(5, 211))
         self.assertTrue(diffie_hellman_key_exchange(11, 971))
 
+class TestNumberOfDigits(unittest.TestCase):
+    """[summary]
+    Test for the file num_digits.py
+
+    Arguments:
+        unittest {[type]} -- [description]
+    """
+    def test_num_digits(self):
+        self.assertEqual(2,num_digits(12))
+        self.assertEqual(5,num_digits(99999))
+        self.assertEqual(1,num_digits(8))
+
 if __name__ == "__main__":
     unittest.main()
 
