#include<graphics.h>
#include<stdlib.h>
#include<stdio.h>
#include<conio.h>
#include<math.h>

void main(void)
{
int gd=DETECT,gm;

/*First Number*/
double pxs0,vxs0,axs0;
double pys0,vys0,ays0;
/*double pzs0,vzs0,azs0  */;

/*Sigma Number*/
double pxs,vxs,axs;
double pys,vys,ays;
/*double pzs,vzs,azs;*/

/*parameters*/
double speedtheta,speedbigth;
double deltatimedays;
double howlong,counter;

/*constant numbers*/
double speedearth;
	speedearth = 2*3.141592/365.251;
	/*printf("%lf",speedearth   ,"\n")*/;
	/*Unit   is 1 AU*/;

double gconst,sungravity;
	 gconst=5.2/(100000000);
	 sungravity=3.3*(100000)*gconst*speedearth;

 initgraph(&gd,&gm,"")     ;

/*=====*/;

	/*firstspeed-vector cerestron s*/;
/*SpeedTheata*/;
printf("\n vecter speed degree -180 to +180??\n");
scanf("%lf",&speedtheta);

/*SpeedBigth*/;
printf("\n speed-bigth 0 to 10 Unit is EarthSpeed?\n");
scanf("%lf",&speedbigth);

pxs0=1;
pys0=0;
vxs0=speedearth*speedbigth*cos(2*3.141592*(speedtheta+90)/360);
vys0=speedearth*speedbigth*sin(2*3.141592*(speedtheta+90)/360);

       /*	printf("%lf %lf %lf",vxs0,vys0,speedearth)*/;

	/*time parameters*/
	/*deltatimedays first:Nxet days of earth*/;
	 deltatimedays=.25;
			  printf("%lf",deltatimedays);
 printf("\n HOWLONG by years ?\n");
 scanf("%lf",&howlong  );

	 howlong=howlong*365.251;
	 printf("%lf",howlong);

/*moniter scale*/
int xmoni,ymoni;
double ktemp;
int howauperhalfxmoni;
 howauperhalfxmoni=5;
 ktemp = 640*.5/howauperhalfxmoni;
xmoni=640;ymoni=480;
circle(int(xmoni/2+.5),(int(ymoni/2-.5)),int(ktemp+.5));
 int dotx,doty;
 /*======main core ====================================
	  counter is 0 than next;
	  s:sigma-mean*/

	 pxs=pxs0;pys=pys0;
	 vxs=vxs0;vys=vys0;
	 /*printf("%lf",vys)*/;
 /*=================================================*/;
	 double d,ax,ay;
	 counter =0;
	 stepagain:;
 /*== important core !!===============================*/

	 d=(pxs*pxs)+(pys*pys);
/*printf("%lf",d,"\n")*/;

	 ax=-sungravity*pxs/(d*sqrt(d));
	 ay=-sungravity*pys/(d*sqrt(d));

	 axs=ax;
	 ays=ay;

	 vxs=vxs+axs*deltatimedays;
	 vys=vys+ays*deltatimedays;
	 pxs=pxs+vxs*deltatimedays;
	 pys=pys+vys*deltatimedays;

 /* =====Graphics======;*/

	 dotx=int(xmoni/2+ktemp*pxs+.5);
	 doty=int(ymoni/2-ktemp*pys+.5);

	 putpixel(dotx,doty,4);

/*=====Graphics end======*/

if (howlong<counter )goto end;
counter=counter+deltatimedays;
goto stepagain;

/*==========================================*/
end:;
printf("\nhit any key \n");
getch();
closegraph();
}