/* 

  Find a specific number of solutions in Picat.

  Usage:
     init_fail2(N):
       - N > 0: try to find N solutions
       - N = 0: try to find all solutions
     fail2(): 
       - as fail/0 but with the restriction of number of solution

  This Picat model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/


% import util.
% import cp.


main => go.


go =>

  init_fail2(3), % find 3 solutions  
  member(A,1..10),

  println(A),

  fail2(),

  
  nl.


go2 =>

  init_fail2(0), % find all solutions  
  member(A,1..10),

  println(A),

  fail2(),

  
  nl.


init_fail2(N) => 
  % printf("Find %d solutions\n", N), 
  if N > 0 then get_global_map().put(num_solutions,N) end.

fail2() =>
   M = get_global_map(),
   if M.has_key(num_solutions) then
     N = M.get(num_solutions),
     if  N =< 1 then
        true
     else
        M.put(num_solutions,N-1),
        fail
     end
   else
     % fail if there's no init of # solutions
     fail
   end.