mult.py

def mult(v1, v2):
    """vX is array of int pairs, e. g. [(6, 2), [7,3 ]] which is equivalent to vector (6, 6, 7, 7, 7) """
    result = 0

    position1 = -1
    position2 = -1
    counter1 = 0
    counter2 = 0
    while True:
        assert counter1 >= 0 and counter2 >= 0

        if counter1 == 0:
            if position1 == len(v1) - 1 and position2 == len(v2) - 1:
                return result
            position1 += 1
            counter1 = v1[position1][1]

        if counter2 == 0:
            if position1 == len(v1) - 1 and position2 == len(v2) - 1:
                return result
            position2 += 1
            counter2 = v2[position2][1]

        assert position1 < len(v1) and position2 < len(v2), 'Vector size seems not equal!'

        result += v1[position1][0] * v2[position2][0]
        counter1 -= 1
        counter2 -= 1


assert mult([(6, 2), (7, 3)], [(1, 1), (3, 1), (5, 2), (1, 1)]) == 101