133 lines
3.7 KiB
C++
Executable File
133 lines
3.7 KiB
C++
Executable File
/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
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/*
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* Main authors:
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* Christian Schulte <schulte@gecode.org>
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*
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* Copyright:
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* Christian Schulte, 2011
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*
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* This file is part of Gecode, the generic constraint
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* development environment:
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* http://www.gecode.org
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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*/
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#include <gecode/driver.hh>
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#include <gecode/int.hh>
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#include <gecode/minimodel.hh>
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using namespace Gecode;
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/**
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* \brief %Options for Schur's Lemma
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*
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*/
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class SchurOptions : public Options {
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public:
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int c, n; ///< Parameters to be given on command line
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/// Initialize options for example with name \a s
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SchurOptions(const char* s, int c0, int n0)
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: Options(s), c(c0), n(n0) {}
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/// Parse options from arguments \a argv (number is \a argc)
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void parse(int& argc, char* argv[]) {
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Options::parse(argc,argv);
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if (argc < 3)
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return;
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c = atoi(argv[1]);
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n = atoi(argv[2]);
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}
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/// Print help message
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virtual void help(void) {
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Options::help();
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std::cerr << "\t(unsigned int) default: " << c << std::endl
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<< "\t\tparameter c (number of boxes)" << std::endl
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<< "\t(unsigned int) default: " << n << std::endl
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<< "\t\tparameter n (number of balls)" << std::endl;
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}
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};
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/**
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* \brief %Example: Schur's lemma
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*
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* Put \f$n\f$ balls labeled \f${1,\ldots,n}\f$ into \f$c\f$ boxes such
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* that for any triple of balls \f$\langle x, y, z\rangle\f$ with
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* \f$x+y = z\f$, not all are in the same box.
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*
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* This problem has a solution for \f$c=3\f$ if \f$n < 14\f$.
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*
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* See also problem 15 at http://www.csplib.org/.
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*
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* \ingroup Example
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*
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*/
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class Schur : public Script {
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protected:
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/// Array of box per ball
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IntVarArray box;
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public:
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/// Actual model
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Schur(const SchurOptions& opt)
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: Script(opt), box(*this,opt.n,1,opt.c) {
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int n = opt.n;
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// Iterate over balls and find triples
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for (int i=1; i<=n; i++)
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for (int j=1; i+j<=n; j++)
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rel(*this, {box[i-1],box[j-1],box[i+j-1]}, IRT_NQ);
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// Break value symmetries
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precede(*this, box, IntArgs::create(opt.c, 1));
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branch(*this, box, INT_VAR_AFC_SIZE_MAX(opt.decay()), INT_VAL_MIN());
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}
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/// Print solution
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virtual void
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print(std::ostream& os) const {
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os << "\t" << box << std::endl;
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}
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/// Constructor for cloning \a s
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Schur(Schur& s) : Script(s) {
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box.update(*this, s.box);
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}
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/// Copy during cloning
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virtual Space*
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copy(void) {
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return new Schur(*this);
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}
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};
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/** \brief Main-function
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* \relates Schur
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*/
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int
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main(int argc, char* argv[]) {
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SchurOptions opt("Schur's Lemma",3,13);
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opt.parse(argc,argv);
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Script::run<Schur,DFS,SchurOptions>(opt);
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return 0;
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}
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// STATISTICS: example-any
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