Question

Actually it’s quite hard to describe:
I want to implement an algorithm which compares figure by figure of the same position (as I do my calculations in a 10-based system it’s rather the same “power of ten”) of two given integers/number (with the same “length”). It should return the grade of equality as following:

• 4491 and 1020 = 0
• 4491 and 4123 = 1
• 4491 and 4400 = 2
• 4491 and 4493 = 3
• 4491 and 4491 = 4
• 4491 and 4091 = 1

I do not want to do my calculations based on a string-comparison, as I’ll doing this in a way bigger scenario 🙂

Answer 1

public static int Compare(int i1, int i2)
{
    int result = 0;
    while(i1 != 0 && i2 != 0)
    {
        var d1 = i1 % 10;
        var d2 = i2 % 10;
        i1 /= 10;
        i2 /= 10;
        if(d1 == d2)
        {
            ++result;
        }
        else
        {
            result = 0;
        }
    }
    if(i1 != 0 || i2 != 0)
    {
        throw new ArgumentException("Integers must be of same length.");
    }
    return result;
}

Note: it does not handle negative integers

Update: fixed after question update