How to use grep to display all the ports that are used by programs running as a specific user?

Question

C++ / C#

How to use grep to display all the ports that are used by programs running as a specific user?
Command: netstat -natpdisplays all ports in use, and how to use grep to compose a command so that only the user's ports can be displayed.
For example! The user "Vasya" launched two programs using ports 443 and 80, and the user "Petya" launched a program that uses ports 22 and 21. How to grep the terminal to see the ports used by the program running on behalf of "Petya".

Answer 1

int i;
        int tk;
        string c;
        private void Button1_Click(object sender, EventArgs e)
        {
            i = 300;
            c ="5:00";
            
            label1.Text = c;
            timer1.Interval = 1000;
            timer1.Enabled = true;
            timer1.Start();
        }

        private void Timer1_Tick(object sender, EventArgs e)
        {
            
            tk = --i;
            TimeSpan span = TimeSpan.FromMinutes(tk);
            string label = span.ToString(@"hh\:mm");
            label1.Text = label.ToString();
            if (i < 0)
                timer1.Stop();
        }

Answer 2

lsof -i | grep Vasya