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