#include <conio.h>
#include <graphics.h>
int GrafInic () {
int gdriver,gmode;
gdriver=DETECT;
initgraph (&gdriver, &gmode, "");
return graphresult()==grOk;
}
void main () {
if (!GrafInic ()) return;
line (0,0,100,100);
line (100,100,0,100);
line (0,100,0,0);
getch ();
closegraph ();
}