36 apples, 4 different backets, all variants

#include <iostream>
#include <sstream>
using namespace std;

string IntToStr(int i)
{
    stringstream ss;
    ss << i;
    return ss.str();
}

string calculate(int *mas, int i, int max, string s)
{
    if (mas[i]<=max && max!=0)
    {
        if (i>0 && mas[i]!=max)
        {
            string old_s = s;
            for (int d=max/mas[i]; d>=0; d--)
            {
                s= old_s;
                if (d>0) s.append(IntToStr(mas[i])+ "(" + IntToStr(d) + ") ");
                calculate(mas, i-1, max-(d*mas[i]), s );
            }
            return "";
        }
        else
        {
            if (((max+mas[i])%mas[i])==0)
            {
                s.append(IntToStr(mas[i])+"(" + IntToStr(max/mas[i])+ ")");
                cout << s << endl;
                return "";
            }
            else {calculate(mas, i-1, max, s); return "";}
        }
    }
    else
    {
        if (max==0) {cout << s << endl; return "";}
        else if (i>0) { calculate(mas, i-1, max, s); return ""; }
        else return "";
    }

}

int C_PACK[] = {1,2,5,10};
int mas_size = sizeof(C_PACK)/sizeof(int);
int apples = 36;

int main()
{
cout<<"Начало:"<<endl;
calculate(C_PACK, mas_size-1, apples, "Такой вариант: ");
cout<<"Конец."<<endl;
return 0;
}