Python/maths/binary_exponentiation.py
Christian Clauss 93fdc9f2a1 Travis CI: Add pytest --doctest-modules maths (#1020)
* Travis CI: Add pytest --doctest-modules maths

* Update lucas_series.py

* Update lucas_series.py
2019-07-21 11:46:28 +05:30

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616 B
Python

"""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("{}^({}) : {}".format(BASE, POWER, RESULT))