Найти количество чисел, которые по модулю меньше заданного числа

#include<iostream>
using  namespace std;
 
void main()
{
    setlocale(LC_ALL, "Rus");
    int n;
    cin >> n;
    while (n > 0)
    {
        cout << n << " ";
        n--;
    }
}

#include <iostream>
using namespace std;
 
int main()
{    
    int n, num, count1=0, count2=0, sum=0;
    
    cout << "n="; cin >> n;
    
    cout << "Enter " << n << " integer numbers:\n";
    for (int i=1; i <= n; i++)
    {
        cin >> num;
        if (num>-50 && num<50) count1++;
        if (num%3==0 && num%7==0) count2++;
        if (num%7==3) sum+=num;
    } 
    
    cout << "count1=" << count1 << "\n";
    cout << "count2=" << count2 << "\n";
    if(sum) cout << "sum=" << sum << "\n";
    else cout << "Numbers which when divided by 7 give a remainder of 3 are absent\n"; 
        
system("pause");
return 0;
}

#include <iostream>
using namespace std;
 
int main()
{    
    int n, num, count1=0, count2=0, sum=0;
    
    cout << "n="; cin >> n;
    
//    cout << "Enter " << n << " integer numbers:\n";
    for (int i=1; i <= n; /*i++*/)
    {
//        cin >> num;
        num = --n;
        if (num>-50 && num<50) count1++;
        if (num%3==0 && num%7==0) count2++;
        if (num%7==3) sum+=num;
    } 
    
    cout << "count1=" << count1 << "\n";
    cout << "count2=" << count2 << "\n";
    if(sum) cout << "sum=" << sum << "\n";
    else cout << "Numbers which when divided by 7 give a remainder of 3 are absent\n"; 
        
system("pause");
return 0;
}