RosettaCodeData/Task/Knapsack-problem-Bounded/Prolog/knapsack-problem-bounded-1.pro

77 lines
2.3 KiB
Prolog

:- use_module(library(clpfd)).
% tuples (name, weights, value, nb pieces).
knapsack :-
L = [( map, 9, 150, 1),
( compass, 13, 35, 1),
( water, 153, 200, 2),
( sandwich, 50, 60, 2),
( glucose, 15, 60, 2),
( tin, 68, 45, 3),
( banana, 27, 60, 3),
( apple, 39, 40, 3),
( cheese, 23, 30, 1),
( beer, 52, 10, 3),
( 'suntan cream', 11, 70, 1),
( camera, 32, 30, 1),
( 'T-shirt', 24, 15, 2),
( trousers, 48, 10, 2),
( umbrella, 73, 40, 1),
( 'waterproof trousers', 42, 70, 1),
( 'waterproof overclothes', 43, 75, 1),
( 'note-case', 22, 80, 1),
( sunglasses, 7, 20, 1),
( towel, 18, 12, 2),
( socks, 4, 50, 1),
( book, 30, 10, 2)],
% Takes is the list of the numbers of each items
% these numbers are between 0 and the 4th value of the tuples of the items
maplist(collect, L, Ws, Vs, Takes),
scalar_product(Ws, Takes, #=<, 400),
scalar_product(Vs, Takes, #=, VM),
% to have statistics on the resolution of the problem.
time(labeling([max(VM), down], Takes)),
scalar_product(Ws, Takes, #=, WM),
%% displayinf of the results.
compute_lenword(L, 0, Len),
sformat(A1, '~~w~~t~~~w|', [Len]),
sformat(A2, '~~t~~w~~~w|', [4]),
sformat(A3, '~~t~~w~~~w|', [5]),
print_results(A1,A2,A3, L, Takes, WM, VM).
collect((_, W, V, N), W, V, Take) :-
Take in 0..N.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
compute_lenword([], N, N).
compute_lenword([(Name, _, _, _)|T], N, NF):-
atom_length(Name, L),
( L > N -> N1 = L; N1 = N),
compute_lenword(T, N1, NF).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
print_results(A1,A2,A3, [], [], WM, WR) :-
sformat(W0, '~w ', [' ']),
sformat(W1, A1, [' ']),
sformat(W2, A2, [WM]),
sformat(W3, A3, [WR]),
format('~w~w~w~w~n', [W0,W1,W2,W3]).
print_results(A1,A2,A3, [_H|T], [0|TR], WM, VM) :-
!,
print_results(A1,A2,A3, T, TR, WM, VM).
print_results(A1, A2, A3, [(Name, W, V, _)|T], [N|TR], WM, VM) :-
sformat(W0, '~w ', [N]),
sformat(W1, A1, [Name]),
sformat(W2, A2, [W]),
sformat(W3, A3, [V]),
format('~w~w~w~w~n', [W0,W1,W2,W3]),
print_results(A1, A2, A3, T, TR, WM, VM).