xor.py

xor.py

""" xor.py

My attempt to complete the challenge at:

https://www.geeksforgeeks.org/calculate-xor-1-n/
"""
import timeit
from functools import reduce


def mod(n):
    """use the modulos to speed up the calculation"""
    remainder = n % 4
    if remainder == 0:
        return n
    elif remainder == 1:
        return 1
    elif remainder == 2:
        return n + 1
    elif remainder == 3:
        return 0
    else:
        return normal(n)


def normal(n):
    """normal brute force attempt"""
    nums = range(1, n+1)
    return reduce(xor, nums)


def xor(a, b):
    """calculates the xor of two numbers"""
    return  a ^ b


def normal_times(n):
    setup_code = """
from __main__ import normal, xor
    """
    test_code = """
n = {}
x = normal(n)
    """.format(n)
    ntimes = timeit.repeat(
        setup = setup_code,
        stmt = test_code,
        repeat = 3,
        number = 10000
    )
    print(f' normal: {min(ntimes)}')


def mod_times(n):
    setup_code = """
from __main__ import mod, normal, xor
    """
    test_code = """
n = {}
x = mod(n)
    """.format(n)
    ntimes = timeit.repeat(
        setup = setup_code,
        stmt = test_code,
        repeat = 3,
        number = 10000
    )
    print(f'modulos: {min(ntimes)}')


if __name__ == '__main__':
    n = 6
    normal_times(n)
    mod_times(n)
    n_xor = normal(n)
    m_xor = mod(n)
    print(f'normal({n}) => {n_xor}')
    print(f'   mod({n}) => {m_xor}')