Python/maths/binary_exponentiation.py

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"""Binary Exponentiation."""
# Author : Junth Basnet
# Time Complexity : O(logn)
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def binary_exponentiation(a, n):
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if n == 0:
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return 1
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elif n % 2 == 1:
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return binary_exponentiation(a, n - 1) * a
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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}")