Update binary_exponentiation.py (#10342)

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

Author: ialoko

maths/binary_exponentiation.py

@@ -6,10 +6,21 @@
 
 def binary_exponentiation(a: int, n: int) -> int:
     """
+    Compute a number raised by some quantity
+    >>> binary_exponentiation(-1, 3)
+    -1
+    >>> binary_exponentiation(-1, 4)
+    1
+    >>> binary_exponentiation(2, 2)
+    4
     >>> binary_exponentiation(3, 5)
     243
     >>> binary_exponentiation(10, 3)
     1000
+    >>> binary_exponentiation(5e3, 1)
+    5000.0
+    >>> binary_exponentiation(-5e3, 1)
+    -5000.0
     """
     if n == 0:
         return 1
@@ -28,7 +39,7 @@ def binary_exponentiation(a: int, n: int) -> int:
     doctest.testmod()
 
     try:
-        BASE = int(input("Enter Base : ").strip())
+        BASE = int(float(input("Enter Base : ").strip()))
         POWER = int(input("Enter Power : ").strip())
     except ValueError:
         print("Invalid literal for integer")