import numpy as np
import multiprocessing
import time
from time import time


def multiplication(first, second, res, start, stop, size):
    for i in range(start, stop):
        for j in range(size):
            res[i][j] = 0
            for k in range(size):
                res[i][j] += first[i][k] * second[k][j]


if __name__ == "__main__":
    sizes = [100, 300, 500]
    threads_counts = [1, 3, 5, 7, 9]
    for threads in threads_counts:
        print(f'Количество потоков: {threads}')
        for size in sizes:
            A = np.random.randint(10, size=(size, size))
            B = np.random.randint(10, size=(size, size))
            if threads == 1:
                res = np.zeros((size, size))
                start = time()
                multiplication(A, B, res, 0, size, size)
                stop = time()
                print(f'Размер: {size}x{size}, время выполнения: {stop - start}')

            else:
                offset = int(size / threads)
                offset_last = size % threads + offset

                processes = []
                res = np.zeros((size, size))
                start = time()
                for i in range(threads):
                    start_ = i * offset
                    stop_ = start_ + offset_last if i == threads - 1 else start_ + offset

                    process = multiprocessing.Process(target=multiplication, args=(A, B, res, start_, stop_, size))
                    processes.append(process)
                    process.start()

                for p in processes:
                    p.join()

                stop = time()

                print(f'Размер: {size}x{size}, время выполнения: {stop - start}')
        print()