%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% The SEND + MORE = MONEY puzzle.
% Solve the equation by assigning a distinct digit between 
% 0 and 9 to each letter.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

:- consult_lib.

solve_puzzle(S,E,N,D,M,O,R,Y):-
    subset({S,E,N,D,M,O,R,Y},int(0,9)) &
    size({S,E,N,D,M,O,R,Y},8)! &
    S neq 0 & M neq 0 &
    X is M*10000 + O*1000 + N*100 + E*10 + Y &
    Z is S*1000 + E*100 + N*10 + D + M*1000 + O*100 + R*10 + E &
    X = Z.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
/*
Example
 
{log}=> solve_puzzle(S,E,N,D,M,O,R,Y).

Constraint: []
D = 7,  
E = 5,  
M = 1,  
N = 6,  
O = 0,  
R = 8,  
S = 9,  
Y = 2

Another solution?  (y/n)y

no
*/