Getting Odd numbers in a array?

I am begginer,I am faced with a challenge to take few numbers and multiply the odd numbers in them to apply the lunhs alogrithm.

Ex- If user inputs 100034341341313413941391341393413.
Is there any way I can take this input and specifically filter out the numbers in the odd places and even places and add them ?

Please just show me the way or how I can get it the number in a array and approach it.The rest i’ll figure out.

Thanks in advance.

>Solution :

Other approaches can be found in here.

void getSum(int n) {
 
    // If n is odd then the last digit
    // will be odd positioned
    bool isOdd = (n % 2 == 1) ? true : false;
 
    // To store the respective sums
    int sumOdd = 0;
    int sumEven = 0;
 
    // While there are digits left process
    while (n != 0) {
 
        // If current digit is odd positioned
        if (isOdd)
            sumOdd += n % 10;
 
        // Even positioned digit
        else
            sumEven += n % 10;
 
        // Invert state
        isOdd = !isOdd;
 
        // Remove last digit
        n /= 10;
    }
 
    cout << "Sum odd = " << sumOdd << "\n";
    cout << "Sum even = " << sumEven;
}