Graphics.h c++ undefined reference to various functions like line(),initgraph()

Question

#include<graphics.h>
#include<stdio.h>

main()
{
int gd=DETECT,gm;
int i,x,y;
initgraph(&gd,&gm,"");
line(0,0,640,0);
line(0,0,0,480);
line(639,0,639,480);
line(639,479,0,479);
for(i=0;i<=1000;i++)
{
   x=rand()%639;
   y=rand()%480;
   putpixel(x,y,15);
}
  getch();
  closegraph();
}

The Following is a Basic Graphic Program,It Shows the Errors as

1. undefined reference to 'initgraph'
2. undefined reference to 'closegraph'
3. undefined reference to 'line'[4 times]

4. undefined reference to 'putpixel'

   Compiler : CodeBlocks; Language:c++;

---

I Have Copied the graphics.h and winbgim.h in include folder and the libbgi.a in the lib folder also i have linked all the libraries required to be linked. Please Help.

Answer 1

Change

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

to

initgraph(&gd,&gm,NULL);

for compiling:

g++ -o filename filename.cpp -lgraph

to execute:

./filename