Vector<T>& mulVector(const Vector<T>& vector) const {

    T* tmp = this->array;
    T* vec, res;

    char* argv[1]; argv[0] = nullptr;
    int argc = 0;
    MPI_Init(&argc, &argv);
    unsigned amount, rank;

    MPI_Comm_size(MPI_COMM_WORLD, &amount);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    unsigned lines = size / amount;
    if (rank == 0) {
        T* vec = tmp;
        for (unsigned it = 1; it != amount; ++it)
            MPI_Send(tmp + it * lines * size, lines * size, MPI_DOUBLE, it, 1, MPI_COMM_WORLD);
    }
    else {
        T* vec = tmp + rank * lines * size;
        MPI_Recv(vec, lines * size, MPI_DOUBLE, 0, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
    }

    for (unsigned it = 0; it != lines; ++it)
        for (unsigned j = 0; j != size; ++j)
            res[it] += vec[it * size + j] * vector[j];


    if (rank != 0) {
        MPI_Send(res, lines, MPI_DOUBLE, 0, 2, MPI_COMM_WORLD);
    }

    else {
        T* final = T[size * size];
        for (unsigned it = 1; it != amount; ++it)
            MPI_Recv(final + it * lines * size, lines * size, MPI_DOUBLE, it, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
        Vector<T>& New = *(new Vector<T>(final, size));
    }