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56"""
Calculates the sum of two non-negative integers using bitwise operators
Wikipedia explanation: https://en.wikipedia.org/wiki/Binary_number
"""
def bitwise_addition_recursive(number: int, other_number: int) -> int:
"""
>>> bitwise_addition_recursive(4, 5)
9
>>> bitwise_addition_recursive(8, 9)
17
>>> bitwise_addition_recursive(0, 4)
4
>>> bitwise_addition_recursive(4.5, 9)
Traceback (most recent call last):
...
TypeError: Both arguments MUST be integers!
>>> bitwise_addition_recursive('4', 9)
Traceback (most recent call last):
...
TypeError: Both arguments MUST be integers!
>>> bitwise_addition_recursive('4.5', 9)
Traceback (most recent call last):
...
TypeError: Both arguments MUST be integers!
>>> bitwise_addition_recursive(-1, 9)
Traceback (most recent call last):
...
ValueError: Both arguments MUST be non-negative!
>>> bitwise_addition_recursive(1, -9)
Traceback (most recent call last):
...
ValueError: Both arguments MUST be non-negative!
"""
if not isinstance(number, int) or not isinstance(other_number, int):
raise TypeError("Both arguments MUST be integers!")
if number < 0 or other_number < 0:
raise ValueError("Both arguments MUST be non-negative!")
bitwise_sum = number ^ other_number
carry = number & other_number
if carry == 0:
return bitwise_sum
return bitwise_addition_recursive(bitwise_sum, carry << 1)
if __name__ == "__main__":
import doctest
doctest.testmod()