:- module(task1, []).
:- use_module(library(clpfd)).

main :-
    writeln('task 1'),
    findall([Ones,Fives,Tens,Twenties], 
            (payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]), label([Ones,Fives,Tens,Twenties])), 
            Solutions),
    forall(member(Sol, Solutions), (write('Solution: '), writeln(Sol))).

payment(Sum, Coins) :-
    payment_acc(0, Sum, Coins).

payment_acc(Acc, Sum, []) :-
    Acc #= Sum.

payment_acc(Acc, Sum, [coin(Count, Value, Available)|Tail]) :-
    Count in 0..Available,
    NewAcc #= Acc + Count * Value,
    payment_acc(NewAcc, Sum, Tail).

% ?- payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]).
% ?- payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]), label([Ones, Fives, Tens, Twenties]).