/*

  Crossbar problem Picat.

  Prolog/FD benchmark problem (crossbar.pl in B Prolog)

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

*/

import cp.


main => go.

go =>

   N = 20,
   List= [V1,V2,V3,V4,V5,V6,V7,V8,V9,V10,
          V11,V12,V13,V14,V15,V16,V17,V18,V19,V20],
   List :: 0..N,

   V1 :: [2,4,6,7,8,9,10,11,16,18,20],
   V2 :: [2,3,4,8,10,12,17,19,20],
   V3 :: [2,3,4,6,8,9,11,17,18],
   V4 :: [1,3,4,5,6,7,9,10,11,13,18],
   V5 :: [1,5,6,10,12,13,14,17,18,19,20],
   V6 :: [1,3,10,12,15,16,19,20],
   V7 :: [5,8,9,10,17],
   V8 :: [1,2,5,6,7,12,14,15,16,17],
   V9 :: [1,2,3,4,5,7,11,12,13,14,16,17,20],
   V10 :: [4,5,8,9,10,11,13,17,18,19,20],
   V11 :: [2,4,6,7,8,10,12,14,17,18,20],
   V12 :: [3,7,8,9,10,13,14,15,18,20],
   V13 :: [2,3,6,7,8,9,11,13,16,20],
   V14 :: [2,3,5,6,8,9,12,13,15,16,17,18],
   V15 :: [2,7,8,10,12,13,14,15,16,17,18,20],
   V16 :: [1,2,6,11,13,16,17,19,20],
   V17 :: [1,3,6,9,13,19],
   V18 :: [1,3,6,7,8,10,13,14,19],
   V19 :: [1,2,3,4,5,6,7,9,11,12,14,16,17,19,20],
   V20 :: [3,5,6,7,8,9,11,12,13,14,16,18,20],

   all_different(List),

   solve(List),

   writeln(List),
   nl.