#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <graphics.h>
void main() {
int    GraphDriver;             /* The Graphics device driver           */
int    GraphMode;               /* The Graphics mode value              */
struct viewporttype vp;
struct point { int x,y; } p1,p2;
int x;

  printf("give me the first point--->"); scanf("%d %d",&p1.x,&p1.y);
  printf("give me the second point--->"); scanf("%d %d",&p2.x,&p2.y);
  printf("give me the reflex (x,y) point (x==y) -->"); scanf("%d",&x);
  getche();

  GraphDriver = DETECT;                 /* Request auto-detection       */
  initgraph( &GraphDriver, &GraphMode, "" );
  setcolor(YELLOW); line(p1.x,p1.y,p2.x,p2.y); getche();

  setcolor(CYAN);
  line(0,x,639,x); line(x,0,x,479); putpixel(x,x,10); getche();

  setcolor(GREEN); line(2*x-p1.x,2*x-p1.y,2*x-p2.x,2*x-p2.y); getche();
  closegraph();                 /* Return the system to text mode       */
}