#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 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);

	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);

     }

    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);
}