% 
% Some explorations of ISBN13 in MiniZinc.
% 

% See
% http://en.wikipedia.org/wiki/ISBN


% This MiniZinc model was created by Hakan Kjellerstrand, hakank@bonetmail.com
% See also my MiniZinc page: http://www.hakank.org/minizinc
%

% include "globals.mzn"; 

int: n = 13;
array[1..n] of var 0..9: isbn;
var 1..9: mult0;
var 1..9: mult1;

solve satisfy;
% solve :: int_search(x, "first_fail", "indomain", "complete") satisfy;

constraint

   % isbn =   [9,7,8,0,5,2,1,6,4,4,0,8,2]
   isbn = [9,7,8,1,5,5,8,6,0,8,9,0,0]
   /\
   isbn[n] = (10 - sum(i in 1..n-1) (
                     if i mod 2 = 0 then
                       isbn[i] * mult0 % 3
                     else
                       isbn[i] * mult1 % 1
                     endif
                   ) mod 10) mod 10
;


output [
  "isbn: ", show(isbn), "\n",
  "mult0: ", show (mult0), " mult1: ", show(mult1), "\n"
];