Problemer med mergesort

void mergesort (int l, int r)
{
    if (r > l)
    {
       
        int mid = (l+r)/2;
        mergesort(l, mid);
        mergesort(mid+1, r);
        merge (l,mid,r);
    }
   
    return;
}

void merge (int l, int mid, int r)
{
    Farmer farmer_temp[5000];
    int i = l;
    int j = mid;
    int k = l;
    //cout << "Merge called, l: " << endl;// << l << " mid: " << mid << " r: " << r << endl;
    while (i<=mid && j<=r)
    {
        if (farmers[i].price < farmers[j].price)
        {
            farmer_temp[k].price = farmers[i].price;
            farmer_temp[k].milk = farmers[i].milk;
            //cout << "i<j " << farmers[i].price << " " << farmers[j].price << endl;
            i++;
           
        }
        else
        {
            farmer_temp[k].price = farmers[j].price;
            farmer_temp[k].milk = farmers[j].milk;
            //cout << "i>j " << farmers[i].price << " " << farmers[j].price << endl;
            j++;
           
        }
        k++;
    }
   
    if (i>mid)
    {
        for (; j<=r; j++, k++)
        {
            farmer_temp[k].price = farmers[j].price;
            farmer_temp[k].milk = farmers[j].milk;
        }
    }
    else
    {
        for (; i<=mid; i++, k++)
        {
            farmer_temp[k].price = farmers[i].price;
            farmer_temp[k].milk = farmers[i].milk;
        }
    }
   
    for (i = l; i<=r; i++)
    {
        farmers[i].price = farmer_temp[i].price;
        farmers[i].milk = farmer_temp[i].milk;
        cout << "Array being copied " << farmer_temp[i].price << " " << farmer_temp[i].milk << " , i: " << i << endl;
    }
   
   
}

Jeg har lavet en lille mergesort funktion som sorter et array af structs efter structmedlemmet pris, men når jeg printer det sorterede array får jeg en del dubletter:

Her er pristallene før de bliver sortet:

5
9
12
4
6
3
19

og her efter:

5
5
5
12
3
6
3

Er der nogle der kan spotte fejlen?