#include  <math.h>
#include<dos.h>
#include<iostream.h>
#include  <graphics.h>
#include<conio.h>
void show(int i,float h, float v);
void erease(int i, float h, float v);
void planeshow(int i);
void ereasep(int i);

void main(void)
{
    int   driver = DETECT,mode;
    int   i,j,n;
    cout<<"Please enter the number of bullets \n";
    cout<<"Suggested value [1, 20]\n";
    cin>>n;

    initgraph(&driver,&mode,"a:\\bgi");
  //  d:\\BC31\\bgi");

      setcolor(WHITE);
      line(1,400,400,400);
    for ( i = 0; i < 80; i++ )
     {
	for (j=0; j<n; j++)
	if ((i-3*j) >0)  show(i-3*j, 5.0+j, 9.0+0.5*j);
	 setcolor(YELLOW);
	 planeshow(5*i);
	 setcolor(BLUE);
         if (i-9>0) planeshow(5*(i-9));
	delay (300);
	for (j=0; j<n; j++)
	if ((i-3*j) >0)  erease(i-3*j, 5.0+j, 9.0+0.5*j);

	if (i>10) erease(i-10, 10.0, 8.0);
	ereasep(5*i);
	if ( (i-9)>0 ) ereasep(5*(i-9));
     }

    closegraph();
}
void show(int i, float h, float v)
{    int x, y;

    x=h*i;
    y=v*i-0.15*i*i;
    setcolor(RED);
    circle(400-x,400-y,2);

}
void erease(int i, float h, float v)
{
   int x, y;
    x=h*i;
    y=v*i-0.15*i*i;
   setcolor(BLACK);
   circle(400-x,400-y,2);
}
void planeshow(int i)
{
    int j;

    circle(i+5, 202, 2);
    circle(i+3, 204, 2);

    for (j=0; j<=8; j++)
    circle(i+j, 200, 2);

    circle(i+5, 198, 2);
    circle(i+3, 196, 2);
}
void ereasep(int i)
{
    int j;
     setcolor(BLACK);
    circle(i+5, 202, 2);
    circle(i+3, 204, 2);

    for (j=0; j<=8; j++)
    circle(i+j, 200, 2);

    circle(i+5, 198, 2);
    circle(i+3, 196, 2);
}