Вычисление произведения чисел больше 15

#include <iostream>
using namespace std;
int main()
{
    int n, sum = 0;
    do
    {
        cin >> n;
        if (n > 10 && n < 25)
            sum += n;
    } while (n != 0);
    cout << "Sum = " << sum;
}

#include <iostream>
#include <cfloat>
using namespace std;
 
int main()
{
    double a, sum=0., mult=1., min=DBL_MAX;    
    
    cout << "Enter numbers (0 - Exit):\n";
    while (cin >> a && a)
    {        
        if (a>10. && a<25.) sum+=a;
        if (a>15.) mult*=a;
        if (a<min) min=a;        
    } 
    
    if (sum) cout << "sum=" << sum << "\n";
    else cout << "Sequence doesn't contain numbers on the interval (10,25)\n";
    if (mult!=1.) cout <<  "mult=" << mult << "\n";
    else cout << "Sequence doesn't contain numbers greater 15\n";
    cout << "min=" << min << "\n";
    
system("pause");
return 0;
}

#include <iostream>
int main()
{
    int n, sum = 0, mul = 1, k = 0, min = 0;
    do
    {
        std::cin >> n;
        if (n > 10 && n < 25)
            sum += n;
        if (n > 15) mul *= n;
        if (n && (k == 0 || n < min)) min = n;
        k++;
    } while (n != 0);
    if (sum) std::cout << "Sum = " << sum << std::endl;
    else std::cout << "No sum !" << std::endl;
    if (mul != 1) std::cout << "Mul = " << mul << std::endl;
    else std::cout << "No mul !" << std::endl;
    if (min) std::cout << "Min = " << min << std::endl;
    else std::cout << "No min !" << std::endl;
    return 0;
}