Understanding - Advanced, exercise 13

Text

The variable my_mat_string contains a string of ten 0-9 digits (e.g. "0000123456"). Study the execution of the following functions when they are called as follows: f(my_mat_string).

def f(mat_string):
    c = 0
    lst = list()

    for chr in mat_string:
        n = int(chr)
        lst.append(n)
        if n / 2 != n // 2:
            c = c + 1

    return g(lst, c)


def g(mat_list, c):
    if c <= 0 or len(mat_list) == 0:
        return 0
    else:
        v = 0
        result = list()

        for i in mat_list:
            if v > 0:
                result.append(i)
            if i > 0 and v == 0:
                v = i

        return v + g(result, c - 1)

Hints

The function f transform the input string in another data structure, and counts something from it. The function g, that is called by the function f, is a recursive function.

Additional material

The runnable Python file is available online. You can run it executing the command python exercise_13.py in a shell, and then following the instructions on screen to specify the intended input.