def matrix_times_matrix(m1: Matrix, m2: Matrix) -> Matrix:
    nr1, nc1 = shape(m1)
    nr2, nc2 = shape(m2)
    assert nc1 == nr2, "must have (# of columns in m1) == (# of rows in m2)"

    def entry_fn(i: int, j: int) -> float:
        """dot product of i-th row of m1 with j-th column of m2"""
        return sum(m1[i][k] * m2[k][j] for k in range(nc1))

    return make_matrix(nr1, nc2, entry_fn)
def matrix_times_matrix(m1: Matrix, m2: Matrix) -> Matrix:
    nr1, nc1 = shape(m1)
    nr2, nc2 = shape(m2)
    assert nc1 == nr2, "liczba kolumn m1 musi być równa liczbie wierszy m2"

    def entry_fn(i: int, j: int) -> float:
        """Wynik funkcji dot na i-tym rzędzie macierzy m1 i j-tej kolumnie macierzy m2"""
        return sum(m1[i][k] * m2[k][j] for k in range(nc1))

    return make_matrix(nr1, nc2, entry_fn)
def matrix_times_matrix(m1: Matrix, m2: Matrix) -> Matrix:
    nr1, nc1 = shape(m1)
    nr2, nc2 = shape(m2)
    assert nc1 == nr2, "must have (# of columns in m1) == (# of rows in m2)"

    def entry_fn(i: int, j: int) -> float:
        """dot product of i-th row of m1 with j-th column of m2"""
        return sum(m1[i][k] * m2[k][j] for k in range(nc1))

    return make_matrix(nr1, nc2, entry_fn)
def matrix_times_vector(m: Matrix, v: Vector) -> Vector:
    nr, nc = shape(m)
    n = len(v)
    assert nc == n, "must have (# of cols in m) == (# of elements in v)"

    return [dot(row, v) for row in m]  # output has length nr
def matrix_times_vector(m: Matrix, v: Vector) -> Vector:
    nr, nc = shape(m)
    n = len(v)
    assert nc == n, "liczba kolumn w m musi być równa liczbie elementów v"

    return [dot(row, v) for row in m]  # wynik ma długość nr
def matrix_times_vector(m: Matrix, v: Vector) -> Vector:
    nr, nc = shape(m)
    n = len(v)
    assert nc == n, "must have (# of cols in m) == (# of elements in v)"

    return [dot(row, v) for row in m]  # output has length nr