binary_exponentiation.py

"""Binary Exponentiation."""

# Author : Junth Basnet
# Time Complexity : O(logn)


def binary_exponentiation(a, n):

 if n == 0:
 return 1

 elif n % 2 == 1:
 return binary_exponentiation(a, n - 1) * a

 else:
 b = binary_exponentiation(a, n / 2)
 return b * b


if __name__ == "__main__":
 try:
 BASE = int(input("Enter Base : ").strip())
 POWER = int(input("Enter Power : ").strip())
 except ValueError:
 print("Invalid literal for integer")

 RESULT = binary_exponentiation(BASE, POWER)
 print(f"{BASE}^({POWER}) : {RESULT}")