facebook interview, task schedule

task_schedule.py

def calc_task_time1(tasks):
    # use a dict, keep all task last run time
    # more space used, less run time expected
    time = 0
    d = dict()

    for t in tasks:
        if t in d:
            last = d[t]
            time = max(last + n, time) + 1
        else:
            time += 1
        d[t] = time

    return time

def calc_task_time1(tasks):
              
    time = 0
    q = deque()
    d = set()

    tasks = tasks[::-1]
    while tasks:
        t = tasks.pop()

        if t in q:
            q.append(None)
            tasks.append(t)
        else:
            q.append(t)

        if len(q) >= n + 1:
            q.popleft()
        time += 1

    return time