Thread: Division Algorithm

i know this post is old, but i have the exact same problem that i am working on.. i need to divide 2^512 +1 by another 49 digit number, but so far only got 2 by 2 digits working.. anyone got any ideas?

Code:

// need to add for loops for array a
#include <iostream.h>
 
int main()
{
    const int sizea = 2;
    const int sizeb = 2;
    
    int a[sizea] = { 5, 7 };
    int b[sizeb] = { 2, 5 };
    int counter[sizea] = { 0 };
    int remainder = 0;
 
//    for (int i = 0; i < sizea; i+=sizeb)
    for (int i = 0; i < sizea; i++)
    {

        // Do division (if necessary)
        int count = 0;
         
        while (a[i] >= b[i])
        {
            if (a[(i+1)] < b[(i+1)])
            {
                a[i] = a[i] - 1;
                a[(i+1)] = a[(i+1)] + 10;
            }
            
            if (a[i]>=b[i])
            {
                a[i] -= b[i];
                a[i + 1] -= b[i + 1];
                ++count;
            }

        }
        
        counter[i + 1] = count;
 
        // Handle remainder
        if (a[i]==0)
        {
            remainder += a[i + 1];
            a[i] = 0;
        }
        else
        {
            a[i + 1] = ( a[i] * 10 ) + a[i + 1];
            remainder = a[i + 1];
            a[i] = 0;
        }
        
    }
 
    // Output
    for (int j = 0; j < sizea; ++j)
    {
        cout << counter[j];
    }
    
    cout << " remainder " << remainder << endl;
 
    return 0;
}

Next time start your own post, but why don't you check out the algorithms used by gmp for division
http://www.swox.com/gmp/manual/Divis...n%20Algorithms
or even look at the source code that they use

thought id carry on the post as it was similar topic....
but anyways....
its part of a uni assignment, where i have to use arrays, so this is what i got so far, if you remove the comment from line 15 and comment out line 16 it works fine for 2 by 2, but i cant get it to work out right for 3 by 2.