Various iterations inclunding benchmarks for getting the binary gap

get_binary_gap.py

#!/usr/bin/env python3

from time import time


def timeit(func):
    """Decorator to time execution of a function and print it out."""
    def timed(*args, **kw):
        start = time()
        result = func(*args, **kw)
        end = time()
        duration = end - start
        print(f"{func.__name__}() took {duration} seconds")
        return result

    return timed


def get_binary_gap0(N):
    # write your code in Python 3.6
    binary_integer_string = "{0:b}".format(N)
    binary_gap = 0
    max_binary_gap = 0

    for char in binary_integer_string:
        if char == "0":
            binary_gap += 1
        else:
            if binary_gap > max_binary_gap:
                max_binary_gap = binary_gap
            binary_gap = 0

    return max_binary_gap


def get_binary_gap1(n: int) -> int:
    binary_integer_string: str = "{0:b}".format(n)
    binary_gap: int = 0
    max_binary_gap: int = 0
    length: int = len(binary_integer_string)

    # skip first char as it's always a 1
    for pos, char in enumerate(binary_integer_string[1:]):
        if char == "0":
            binary_gap += 1
        else:
            if binary_gap > max_binary_gap:
                max_binary_gap = binary_gap
                # stop early if remaining length is not enough for new max
                if binary_gap >= (length-pos-2):
                    return max_binary_gap
            binary_gap = 0

    return max_binary_gap


def get_binary_gap2(n: int) -> int:
    # convert to binary, remove trailing 0, remove leading & trailing 1 (always there), split by 1
    # 1612 -> 110010001100 -> 10010001
    return len(max("{0:b}".format(n).rstrip("0")[1:-1].split("1")))


def get_binary_gap3(n: int) -> int:
    # convert to binary, remove trailing 0, remove leading & trailing 1s (always there), split by 1
    # 1612 -> 110010001100 -> 001000 -> [00, 000]
    return len(max("{0:b}".format(n).rstrip("0").strip("1").split("1")))


def get_binary_gap4(n: int) -> int:
    # convert to binary, remove trailing 0, remove leading & trailing 1s (always there), split by 1
    # 1612 -> 110010001100 -> 001000 -> [00, 000]
    return len(max(bin(n).rstrip("0").strip("1").split("1")))


@timeit
def main0():
    for i in range(1, 21474836):  # 48
        get_binary_gap0(i)


@timeit
def main1():
    for i in range(1, 21474836):  # 48
        get_binary_gap1(i)


@timeit
def main2():
    for i in range(1, 21474836):  # 48
        get_binary_gap2(i)


@timeit
def main3():
    for i in range(1, 21474836):  # 48
        get_binary_gap3(i)


@timeit
def main4():
    for i in range(1, 21474836):  # 48
        get_binary_gap4(i)


if __name__ == '__main__':
    main0()
    main1()  # enumerate is bad, hmkay
    main2()
    main3()
    main4()
    tests = {
        0: 0,
        1: 0,
        32: 0,
        1041: 5,
        2146483647: 4,
        0b10: 0,
        0b101: 1,
        0b10100: 1,
        0b101001: 2,
        0b100101: 2,
    }
    for num, gap in tests.items():
        assert gap == get_binary_gap2(num)