1 /* Frobby: Software for monomial ideal computations.
2 Copyright (C) 2007 Bjarke Hammersholt Roune (www.broune.com)
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see http://www.gnu.org/licenses/.
16 */
17 #include "stdinc.h"
18 #include "FrobeniusAction.h"
19
20 #include "BigIdeal.h"
21 #include "IOFacade.h"
22 #include "SliceFacade.h"
23 #include "SliceParams.h"
24 #include "BigTermRecorder.h"
25 #include "Scanner.h"
26 #include "display.h"
27
FrobeniusAction()28 FrobeniusAction::FrobeniusAction():
29 Action
30 (staticGetName(),
31 "Compute Frobenius number using a Grobner basis algorithm.",
32 "Compute the Frobenius number of the passed-in Frobenius instance. This "
33 "instance\n"
34 "must be preceded in the input by a deg-rev-lex lattice ideal Grobner basis "
35 "as\n"
36 "produced by the program 4ti2.\n\n"
37 "The algorithm for this uses irreducible decomposition to compute the "
38 "Frobenius\n"
39 "number, which is why this action accepts parameters related to that. See "
40 "the\n"
41 "paper \"Solving Thousand Digit Frobenius Problems Using Grobner Bases\"\n"
42 "at www.broune.com for more details.",
43 false),
44
45 _sliceParams(true, false),
46 _displaySolution
47 ("vector",
48 "Display the vector that achieves the optimal value.",
49 false) {
50 _sliceParams.setSplit("frob");
51 }
52
obtainParameters(vector<Parameter * > & parameters)53 void FrobeniusAction::obtainParameters(vector<Parameter*>& parameters) {
54 Action::obtainParameters(parameters);
55 _sliceParams.obtainParameters(parameters);
56
57 parameters.push_back(&_displaySolution);
58 }
59
perform()60 void FrobeniusAction::perform() {
61 displayNote
62 ("The action frobgrob is DEPRECATED, and will be removed in a future "
63 "release of Frobby. Use the action optimize with options "
64 "-chopFirstAndSubtract and -maxStandard instead to get the same effect.");
65
66 SliceParams params(_params);
67 validateSplit(params, true, true);
68
69 vector<mpz_class> instance;
70 BigIdeal ideal;
71
72 IOFacade ioFacade(_printActions);
73 Scanner in("", stdin);
74 ioFacade.readFrobeniusInstanceWithGrobnerBasis(in, ideal, instance);
75 in.expectEOF();
76
77 vector<mpz_class> shiftedDegrees(instance.begin() + 1, instance.end());
78 vector<mpz_class> bigVector;
79
80 BigTermRecorder recorder;
81
82 SliceFacade facade(params, ideal, recorder);
83 mpz_class dummy;
84 facade.solveStandardProgram(shiftedDegrees, dummy, false);
85
86 BigIdeal maxSolution = *(recorder.releaseIdeal());
87
88 ASSERT(maxSolution.getGeneratorCount() == 1);
89 bigVector = maxSolution[0];
90
91 mpz_class frobeniusNumber = -instance[0];
92 for (size_t i = 1; i < instance.size(); ++i)
93 frobeniusNumber += bigVector[i - 1] * instance[i];
94
95 if (_displaySolution) {
96 fputs("(-1", stdout);
97 for (size_t i = 0; i < bigVector.size(); ++i)
98 gmp_fprintf(stdout, ", %Zd", bigVector[i].get_mpz_t());
99 fputs(")\n", stdout);
100 }
101
102 gmp_fprintf(stdout, "%Zd\n", frobeniusNumber.get_mpz_t());
103 }
104
staticGetName()105 const char* FrobeniusAction::staticGetName() {
106 return "frobgrob";
107 }
108
displayAction() const109 bool FrobeniusAction::displayAction() const {
110 return false;
111 }
112