def check_palindrome(string):
    """
    Question 7.5: Check palindromicity of string
    """
    begin = 0
    end = len(string) - 1

    while begin < end:
        while not string[begin].isalnum() and begin < end:
            begin += 1
        while not string[end].isalnum() and begin < end:
            end -= 1

        if string[begin].lower() != string[end].lower():
            return False
        begin += 1
        end -= 1
    return True