C++ graphics initgraph error (syntax or missing-file flaw?)

Question

[SOLVED]

I'm using CodeBlocks (C++) on Win10. I tried to create a simple graphic program - I downloaded a certain graphics package (graphics.h and other two files related to BGI - I added the lib in settings etc.). I tried this program but there seems to be a problem at the line marked. I ported this from Pascal (as my teacher -yes, it's about college-, only shows us Pascal programs) in a correct manner I suppose, or at least partially. The problem is certainly with the pointers (EDIT AFTER SOLVING: it wasn't!, check my answer). I'll give more details if needed.

The Question: Where I did mistakes and how to correct them (what to write, what to add, what to delete) so that it wil work fine? If there is no mistake in the code, but I NEED some files for graphics to work on my compiler, which are the files, where to get them and where to put them?

ERROR (not quite, now's a "warning"):

deprecated conversion from string constant to 'char*' [-Wwrite-strings]

(see code a bit below)

Please read: I would BE VERY GRATEFUL for a fixed version of my program. Refferences are USELESS, so unless you REALLY want to help me (thank you!), leave this page. My only related capacity is to compare two versions of a program that are intended to do the same thing but one has a mistake (or more).

CODE (updated!):

#include<iostream>
#include<graphics.h>
#include<conio.h>
using namespace std;
int main(){
int gr,xmax,ymax,r;
int gm,gd;
gd=DETECT;
gm=0;
initgraph(&gd, gm, "C:\\TC\\BGI"); /*edit(solved): followed the tutorial linked in my answer; not a directory in my PC.*/
gr=graphresult();
if(gr!=grOk) cout<<"Error!";
    else    {xmax=getmaxx();
            ymax=getmaxy();
            cout<<"Resol.: "<<xmax+1<<"x"<<ymax+1;}
setcolor(7);rectangle(0,0,xmax,ymax);setcolor(5);line(0,0,xmax,ymax);line(0,ymax,xmax,0);setcolor(3);
for(r=(ymax+1)/2;r>=0;r--) circle((xmax+1)/2,(ymax+1)/2,r);
getch();
closegraph();
return 0;
}

graphics.h source and guide: http://www.codewithc.com/how-to-include-graphics-h-in-codeblocks/

Answer 1

Solved! Downgraded CB (v16 to v13 I think, not sure if it was necessary) and replaced some files. I followed this tutorial: https://m.youtube.com/watch?v=FxCdMM9H66I It was quite the same as the link in the question but probably (one or more of) those files (graphics.h, winbgim.h, libbgi.a) from the previous link were bugged, had some unobvious errors or so, or were incompatible etcetera), while the files given by the maker of the vid I provided in this answer were corrected. I don't (really want to) know. Now, the warning still appears, BUT the program runs perfectly! I replaced r=0 with r>=0 , this was a minor mistake. (I'll update the question if I still can)

Thanks for... your help! (Can't say "nothing", I'd be mean) :)

EDIT:

Some "cleaner" version that shows the circle (just realised the variant in the question doesn't display the filled circle):

#include<iostream>
#include<graphics.h>
#include<dos.h>
using namespace std;
main(){
int gm,gd,gr,xmax,ymax,r;
gd=DETECT;
gm=0;
initgraph(&gd,&gm,"C:\\TC\\BGI");
gr=graphresult();
if(gr!=grOk) cout<<"Error!";
    else    {xmax=getmaxx();
            ymax=getmaxy();
            cout<<"Res.: "<<xmax+1<<"x"<<ymax+1;}
setcolor(7);
rectangle(0,0,xmax,ymax);
setcolor(5);
line(0,0,xmax,ymax);
line(0,ymax,xmax,0);
setcolor(3);
for(r=(ymax+1)/2;r>=0;r--) circle((xmax+1)/2,(ymax+1)/2,r);
getch();
closegraph();
}

EDIT2: Downgrading not necessary CONFIRMED! :D