/* 

  sendmore benchmark in Picat v3.

  bench/sendmore.pl
  https://github.com/SWI-Prolog/bench

  Changes:
  - replaced digit/1 -> digitx/1
  - added output (write/1 -> print/1)

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

*/

main => go.


go ?=>
  digitx(D), digitx(E), D=\=E,
  sumdigit(0, D, E, Y, C1),
  digitx(N), N=\=Y, N=\=E, N=\=D,
  digitx(R), R=\=N, R=\=Y, R=\=E, R=\=D,
  sumdigit(C1,N, R, E, C2),
  digitx(O), O=\=R, O=\=N, O=\=Y, O=\=E, O=\=D,
  sumdigit(C2,E, O, N, C3),
  leftdigit(S), S=\=O, S=\=R, S=\=N, S=\=Y, S=\=E, S=\=D,
  leftdigit(M), M=\=S, M=\=O, M=\=R, M=\=N, M=\=Y, M=\=E, M=\=D,
  sumdigit(C3,S, M, O, M),
  print(' '),print(S),print(E),print(N),print(D),nl,
  print('+'),print(M),print(O),print(R),print(E),nl,
  print('-----'),nl,
  print(M),print(O),print(N),print(E),print(Y),nl,nl,
  fail,
  
  nl.

go => true.

% """
% Cryptoaddition:
% Find the unique answer to:
%  SEND
% +MORE
% -----
% MONEY
% where each letter is a distinct digit.
% """
top:-
	digitx(D), digitx(E), D=\=E,
	sumdigit(0, D, E, Y, C1),
	digitx(N), N=\=Y, N=\=E, N=\=D,
	digitx(R), R=\=N, R=\=Y, R=\=E, R=\=D,
	sumdigit(C1,N, R, E, C2),
	digitx(O), O=\=R, O=\=N, O=\=Y, O=\=E, O=\=D,
	sumdigit(C2,E, O, N, C3),
	leftdigit(S), S=\=O, S=\=R, S=\=N, S=\=Y, S=\=E, S=\=D,
	leftdigit(M), M=\=S, M=\=O, M=\=R, M=\=N, M=\=Y, M=\=E, M=\=D,
	sumdigit(C3,S, M, O, M),
	% print(' '),print(S),print(E),print(N),print(D),nl,
	% print('+'),print(M),print(O),print(R),print(E),nl,
	% print('-----'),nl,
	% print(M),print(O),print(N),print(E),print(Y),nl,nl,
	fail.
top.

sumdigit(C, A, B, S, D) :-
	X is (C+A+B),
	(X<10
	-> S=X,       D=0
	;  S is X-10, D=1
	).

digitx(0).
digitx(1).
digitx(2).
digitx(3).
digitx(4).
digitx(5).
digitx(6).
digitx(7).
digitx(8).
digitx(9).

leftdigit(1).
leftdigit(2).
leftdigit(3).
leftdigit(4).
leftdigit(5).
leftdigit(6).
leftdigit(7).
leftdigit(8).
leftdigit(9).