C++ in Ubuntu

time delay :

#include <unistd.h>
usleep(3000000); 

Graphics code snippet :

#include <graphics.h>
#include <iostream>
#include <unistd.h>



using namespace std;

int main()
{
 int a,gd,gm=VGAMAX;
 gd=DETECT;
 cout<<"Give a number : ";
 cin>>a;
 initgraph(&gd,&gm,NULL);
 circle(100,100,a);
 usleep(1000000);
 return 0;
}