coding question solution

job_delay.py

# in_string = 'ABC' / 'AAA' / 'ABAF'
# delay = 5
# res 3, 13,

from collections import deque


def calc_processing_time(in_str: str, delay: int) -> int:
    """
    calculating running time for jobs in in_str with delay between consequent jobs
    :param in_str: string of input jobs
    :param delay: number of cycles to wait between 2 jobs of same type
    :return: number of cycles it will take to work through the input sequence
    """
    if len(in_str) <= 1:
        return len(in_str)

    pipe_of_jobs = deque(["" for _ in range(delay + 1)])
    num_operations, job_idx = 0, 0

    # going through all jobs once, worst case all jobs are the same O(delay * len(in_str)) = O(n)
    while job_idx < len(in_str):
        try:
            if pipe_of_jobs.popleft() != '':
                num_operations += 1
        except IndexError:
            pass
        # assuming delay is a const, running time of this check is O(1)
        if in_str[job_idx] in pipe_of_jobs:
            pipe_of_jobs.append('wait')
        else:
            pipe_of_jobs.append(in_str[job_idx])
            job_idx += 1

    # emptying pipe of jobs O(1), delay is const
    while len(pipe_of_jobs) > 0:
        if pipe_of_jobs.popleft() != '':
            num_operations += 1

    return num_operations


if __name__ == '__main__':
    assert calc_processing_time('ABC', 5) == 3
    assert calc_processing_time('ABCA', 5) == 7
    assert calc_processing_time('AAA', 5) == 13
    assert calc_processing_time('AAA', 13) == 29
    assert calc_processing_time('AAA', 2) == 7
    assert calc_processing_time('AAA', 0) == 3
    assert calc_processing_time('AAA', 1) == 5
    assert calc_processing_time('A', 110) == 1
    assert calc_processing_time('AA', 110) == 112
    assert calc_processing_time('AABBCC', 1) == 9
    assert calc_processing_time('AABBCC', 0) == 6
    assert calc_processing_time('A1234567890A', 20) == 22
    assert calc_processing_time('', 2) == 0
    assert calc_processing_time('A', 2) == 1