Weigth_combinations_Task_4

import functools
import itertools
import time
from typing import Sequence, Generator, List, Optional

def stopwatch(func):
    @functools.wraps(func)
    def inner_func(*args, **kwargs):
        start = time.perf_counter()
        result = func(*args, **kwargs)
        end = time.perf_counter()

print(f"Function : {func.__name__}")
        print(f"Finished in : {(end - start):.10f}s")
        return result

return inner_func

@stopwatch
def get_weight_combinations(weights: Sequence[int], outcome_weight: int) -> int:
    combinations = 0
    for length in range(1, len(weights) + 1):
        for combination in itertools.combinations(weights, r=length):
            if sum(combination) == outcome_weight:
                combinations += 1
    return combinations

assert get_weight_combinations(weights=(1, 2, 3, 4), outcome_weight=3) == 2
assert get_weight_combinations(weights=(1, 2, 3, 3, 4), outcome_weight=7) == 4
assert get_weight_combinations((3, 9, 8, 4, 5, 7, 10), 15) == 4

@stopwatch
def get_weight_combinations_generator(
        weights: Sequence[int],
        outcome_weight: int,
        sequence: Optional[List] = None,
        sequence_sum: int = 0
) -> Generator[List[int], None, None]:
    if sequence is None:
        sequence = []
    if sequence_sum == outcome_weight:
        yield sequence
    if sequence_sum >= outcome_weight:
        return
    for i, n in enumerate(weights):
        remaining = weights[i + 1:]
        yield from get_weight_combinations_generator(remaining, outcome_weight, sequence.append(n), sequence_sum + n)

assert len(list(get_weight_combinations_generator(weights=(1, 2, 3, 4), outcome_weight=3))) == 2
assert len(list(get_weight_combinations_generator(weights=(1, 2, 3, 3, 4), outcome_weight=7))) == 4
assert len(list(get_weight_combinations_generator(weights=(3, 9, 8, 4, 5, 7, 10), outcome_weight=15))) == 4

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