first_task.py

from functools import reduce
from itertools import count, permutations
from pprint import pprint


def to_task_name(n):
    return chr(ord('A') + n)


def name_time_cost_to_task(t):
    return {
        'name': t[0],
        'time': t[1],
        'cost': t[2]
    }


def solve_for_ordered_tasks(ordered_tasks):
    total_time = sum(map(lambda t: t['time'], ordered_tasks))

    def reduce_function(acc, t):
        return {
            'time_left': acc['time_left'] - t['time'],
            'total_cost': acc['total_cost'] + (acc['time_left'] - t['time']) * t['cost']
        }

    total_cost = reduce(reduce_function, ordered_tasks, {'time_left': total_time, 'total_cost': 0})['total_cost']

    return {
        'ordered_tasks': ordered_tasks,
        'total_cost': total_cost
    }


def create_tasks_iter(costs, time):
    return map(name_time_cost_to_task, zip(map(to_task_name, count()), time, costs))


def solve(costs, time):
    tasks = create_tasks_iter(costs, time)
    ordered_tasks = sorted(tasks, key=lambda t: t['cost'] / t['time'])
    return solve_for_ordered_tasks(ordered_tasks)


def order_tasks(tasks, order):
    return [next(t for t in tasks if t['name'] == o) for o in order]


def run_test_1():
    costs = [22, 1, 10, 4, 9]
    time = [11, 1, 6, 3, 4]
    ans = solve(costs, time)
    assert ans['total_cost'] == 346, '{} is not equal to {}'.format(ans['total_cost'], 346)
    print("Test 1 passed")


def run_test_2():
    costs = [7, 2, 18, 1, 14, 5]
    time = [4, 3, 9, 1, 6, 3]
    ans = solve(costs, time)
    assert ans['total_cost'] == 376, '{} is not equal to {}'.format(ans['total_cost'], 376)
    print("Test 2 passed")


def get_worst_case(costs, time):
    tasks = list(create_tasks_iter(costs, time))
    order = [t['name'] for t in tasks]
    worst = max((solve_for_ordered_tasks(order_tasks(tasks, o)) for o in permutations(order)),
                key=lambda ans: ans['total_cost'])
    return worst


def main():
    run_test_1()
    run_test_2()

    costs = list(map(int, input('Enter costs: ').split()))
    time = list(map(int, input('Enter times: ').split()))
    pprint(solve(costs, time))

    worst_case = get_worst_case(costs, time)
    pprint(worst_case)

    # while True:
    #     tasks = list(create_tasks_iter(costs, time))
    #     order = [x.upper() for x in input('Enter order: ').split()]
    #     ordered_tasks = order_tasks(tasks, order)
    #     pprint(solve_for_ordered_tasks(ordered_tasks))


if __name__ == '__main__':
    main()