Add automorphic number check algorithm

Author: ShreyasKudahalli

maths/automorphic_number.py

@@ -0,0 +1,24 @@
+def is_automorphic(n: int) -> bool:
+    """
+    Check if a number is an Automorphic Number.
+    A number is automorphic if its square ends with the number itself.
+
+    Examples:
+    >>> is_automorphic(5)
+    True
+    >>> is_automorphic(6)
+    True
+    >>> is_automorphic(76)
+    True
+    >>> is_automorphic(7)
+    False
+
+    Time Complexity: O(d) where d is number of digits
+    """
+    square = n * n
+    return str(square).endswith(str(n))
+
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()