Files
linguist/samples/Prolog/logic-problem.pro
Arfon Smith 9e50e188a8 Merge branch 'master' into 1233-local
Conflicts:
	lib/linguist/language.rb
	lib/linguist/languages.yml
	lib/linguist/samples.json
2014-11-01 10:04:22 -05:00

69 lines
1.7 KiB
Prolog

/**
* Question 1.1
* combiner(+Buddies, -Pairs)
*/
combiner([], []).
combiner([First|Buddies], Pairs):-
make_pairs(First, Buddies, Pairs1),
combiner(Buddies, Pairs2),
concat(Pairs1, Pairs2, Pairs).
/**
* make_pairs(+Buddy, +Buddies, -Pairs)
*/
make_pairs(Buddy, [], []).
make_pairs(Buddy, [First|Buddies], [(Buddy, First)|Pairs]):-
make_pairs(Buddy, Buddies, Pairs).
/**
* concat(+X, +Y, ?T)
*/
concat([], Y, Y).
concat([P|R], Y, [P|T]):-
concat(R, Y, T).
/**
* Question 1.2
* extraire(+AllPossiblePairs, +NbPairs, -Tp, -RemainingPairs)
*/
extraire(AllPossiblePairs, 0, [], AllPossiblePairs).
extraire([PossiblePair|AllPossiblePairs], NbPairs, [PossiblePair|Tp], NewRemainingPairs):-
NbPairs > 0,
NewNbPairs is NbPairs - 1,
extraire(AllPossiblePairs, NewNbPairs, Tp, RemainingPairs),
not(pair_in_array(PossiblePair, Tp)),
delete_pair(RemainingPairs, PossiblePair, NewRemainingPairs).
extraire([PossiblePair|AllPossiblePairs], NbPairs, Tp, [PossiblePair|RemainingPairs]):-
NbPairs > 0,
extraire(AllPossiblePairs, NbPairs, Tp, RemainingPairs),
pair_in_array(PossiblePair, Tp).
/**
* delete_pair(+Pairs, +Pair, -PairsWithoutPair)
*/
delete_pair([], _, []).
delete_pair([Pair|Pairs], Pair, Pairs):-!.
delete_pair([FirstPair|Pairs], Pair, [FirstPair|PairsWithoutPair]):-
delete_pair(Pairs, Pair, PairsWithoutPair).
/**
* pair_in_array(+Pair, +Pairs)
*/
pair_in_array((A, B), [(C, D)|Pairs]):-
(A == C ; B == D ; A == D ; B == C),
!.
pair_in_array(Pair, [FirstPair|Pairs]):-
pair_in_array(Pair, Pairs).
/**
* Question 1.3
* les_tps(+Buddies, -Tps)
*/
les_tps(Buddies, Tps):-
combiner(Buddies, PossiblePairs),
length(Buddies, NbBuddies),
NbPairs is integer(NbBuddies / 2),
findall(Tp, extraire(PossiblePairs, NbPairs, Tp, _), Tps).