#include <graphics.h>
void drawpoly(int numpoints, int *polypoints);
 

drawpoly draws a polygon with numpoints points, using the current line
style and color.
*polypoints points to a sequence of (numpoints * 2) integers. Each pair
of integers gives the x- and y-coordinates of a point on the polygon.
In order to draw a closed figure with n vertices, you must pass n + 1
coordinates to drawpoly where the nth coordinate is equal to the 0th.

/* drawpoly example */
 
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
 
int main(void)
{
   /* request autodetection */
   int gdriver = DETECT, gmode, errorcode;
   int maxx, maxy;
 
   int poly[10];   /* our polygon array */
 
   /* initialize graphics and local variables */
   initgraph(&gdriver, &gmode, "");
 
   /* read result of initialization */
   errorcode = graphresult();
   if (errorcode != grOk){ /* an error occurred */
printf("Graphics error: %s\n", grapherrormsg(errorcode));
 
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
   }
 
   maxx = getmaxx();
   maxy = getmaxy();
   poly[0] = 20;     /* first vertex */
   poly[1] = maxy / 2;
   poly[2] = maxx - 20;    /* second vertex */
   poly[3] = 20;
   poly[4] = maxx - 50;    /* third vertex */
   poly[5] = maxy - 20;
   poly[6] = maxx / 2;     /* fourth vertex */
   poly[7] = maxy / 2;
   poly[8] = poly[0];/* drawpoly doesn't automatically close */
 
   poly[9] = poly[1];/* the polygon, so we close it */
 
   drawpoly(5, poly);   /* draw the polygon */
 
   /* clean up */
   getch();
   closegraph();
   return 0;
}

fillpoly floodfill graphresult setwritemode

  no output of example at the moment
  do not hesitate and add it...