Question

I have an app that will display Lotto Max numbers, I need to make my app generate random numbers but I need the numbers to not repeat. I have my code done and would like to change a little as possible. But any help would be awesome!

    #include <iostream> 
    #include <iomanip>
    #include <cstdlib>
    using namespace std;

    int main()
    {

    {
cout << "*** LOTTO  MAX  INSTA  PICK ***" << endl;
cout<< " " << endl << endl;
    }

     {
 cout << "Your Insta Pick Numbers" << endl;
 cout<< " " << endl << endl;
     }
 for (int counter = 1; counter <= 21; ++ counter)
{

cout << setw(1) << (1 + rand() % 49) << " ";


if (counter % 7 == 0)
        cout << endl;
}
{
    cout<< " " << endl << endl;
}


{
cout << "Your Tag Numbers" << endl;
cout<< " " << endl << endl;
    }
for (int counter = 1; counter <= 9; ++ counter)
{

cout << setw(1) << (0 + rand() % 9)<< " ";


if (counter % 9 == 0)
        cout << endl;

}
{
    cout<< " " << endl << endl;
}
{
    cout << "Thank you for playing!! please check ticket\n a year minus a day            from date of purchase" <<endl;
}
    };

Answer 1

Before using the rand function, you need to seed the generator with a unique value. This is done with the srand functions. Commonly the unique number is the current time as returned by time:

srand(time(0));

Unless you manage to run the application several times in a single second, the result will be unique every time you run the application.