line(0,0,maxx,maxy)

#include < graphics.h > 
#include < stdio.h > 
int main() {
    int i;
    int maxx,
    maxy;
    int graphdriver = DETECT;
    int graphmode;
    initgraph( & graphdriver, &graphmode, "");
    cleardevice();
    maxx = getmaxx();
    /*639*/
    maxy = getmaxy();
    /*479*/
    line(0, 0, maxx, maxy);
    printf("%d,%d", maxx, maxy);
    getch();
    closegraph();
    return 0;
}