Factorial through while

// factorial through while

#include <iostream>

using std::cout;
using std::cin;
using std::endl;

void main()
{
    setlocale(LC_ALL, "Russian");

    int a, i = 0, cntnr;

    cout << "Введите значение: "; cin >> a;

    cntnr = a - 1;

    while (i != cntnr)
    {
        a *= (++i);
    }

    cout << cntnr + 1 << "! = " << a << endl;
}