(* Thomas Nagy, 2005 *)

open Facile;;
open Easy;;

let print _puzzle =
  let n = 9 in
  for i = 0 to n - 1 do
    for j = 0 to n - 1 do
      let c = Fd.int_value _puzzle.(9*i+j) in
      Printf.printf "%d " c
    done;
    print_newline ()
  done;
  flush stdout;;

let puzzle = [|
        5; 3; 0;  0; 7; 0;  0; 0; 0;
        6; 0; 0;  1; 9; 5;  0; 0; 0;
        0; 9; 8;  0; 0; 0;  0; 6; 0;

        8; 0; 0;  0; 6; 0;  0; 0; 3;
        4; 0; 0;  8; 0; 3;  0; 0; 1;
        7; 0; 0;  0; 2; 0;  0; 0; 6;

        0; 6; 0;  0; 0; 0;  2; 8; 0;
        0; 0; 0;  4; 1; 9;  0; 0; 5;
        0; 0; 0;  0; 8; 0;  0; 7; 9;
|];;
let myarr = Fd.array 81  1 9;;

(* fixed values *)
for i=0 to 80 do
        let value = Array.get puzzle i in
        if value > 0 then Cstr.post (fd2e myarr.(i) =~ i2e value);
done;;

(* constraints horizontal, vertical and squares *)
let chooser i x y =
	if i=0 then x*9+y
	else if i=1 then x+y*9
	else (27*(x/3)+3*(x mod 3)) + (9*(y/3)+(y mod 3))
;;

(* add the constraints *)
for c=0 to 2 do
	for i=0 to 8 do
		let arr = Array.init 9 (fun k -> myarr.(chooser c i k)) in
		Cstr.post (Alldiff.cstr arr)
	done
done;;

(* solve *)
let goal = Goals.GlArray.labeling myarr in
if (Goals.solve goal) then print myarr 
else failwith "no solution found"
;;