Add Automorphic Number Check Algorithm

maths/automorphic_number.py

@@ -0,0 +1,40 @@
+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.
+
+    Args:
+        n: A non-negative integer.
+
+    Returns:
+        True if n is automorphic, False otherwise.
+
+    Examples:
+    >>> is_automorphic(5)
+    True
+    >>> is_automorphic(6)
+    True
+    >>> is_automorphic(76)
+    True
+    >>> is_automorphic(7)
+    False
+    >>> is_automorphic(-5)
+    Traceback (most recent call last):
+        ...
+    ValueError: n must be a non-negative integer
+
+    Time Complexity:
+        O(d) where d is the number of digits of n.
+    """
+    if n < 0:
+        raise ValueError("n must be a non-negative integer")
+
+    square = n * n
+    return str(square).endswith(str(n))
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()