#include <iostream>
using namespace std;
int main()
{
    int n1, n2, n3, i=0;
        for (n1 = 1; n1 < 10; n1++)
        {
            for (n2 = 0; n2 < 10; n2++)
            {
                for (n3 = 0; n3 < 10; n3++)
                {
                    cout << i << "   " << n1 << " " << n2 << " " << n3  << endl;
                }
            }
        }
    return 0;
}

what's the problem with this source ?
i want to show from 100 to 999 but it start at 701 !!!

i understood the problem!
it was about my compiler visual studio 2012 !
it just show the last 300 lines !

do you knowany way to fix it ?

i want to show from 100 to 999 but it start at 701 !!!

It doesn't start at 701, that's just where as far back as the command prompt allows you to scroll. Try this and use the Enter key to continue to the next "page":

for (n1 = 1; n1 < 10; n1++)
{
    for (n2 = 0; n2 < 10; n2++)
    {
        for (n3 = 0; n3 < 10; n3++)
        {
            cout << i << "   " << n1 << " " << n2 << " " << n3  << endl;
        }
    }

    cin.get();
}