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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Guido Tack <tack@gecode.org>
*
* Contributing authors:
* Mikael Lagerkvist <lagerkvist@gecode.org>
*
* Copyright:
* Guido Tack, 2004
* Mikael Lagerkivst, 2017
*
* 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/set.hh>
using namespace Gecode;
/// \brief %Options for %Golf example
class GolfOptions : public Options {
protected:
Driver::IntOption _w; //< Number of weeks
Driver::IntOption _g; //< Number of groups
Driver::IntOption _s; //< Number of players per group
public:
/// Constructor
GolfOptions(void)
: Options("Golf"),
_w("w","number of weeks",9),
_g("g","number of groups",8),
_s("s","number of players per group",4) {
add(_w);
add(_g);
add(_s);
}
/// Return number of weeks
int w(void) const { return _w.value(); }
/// Return number of groups
int g(void) const { return _g.value(); }
/// Return number of players per group
int s(void) const { return _s.value(); }
};
/**
* \brief %Example: %Golf tournament
*
* Schedule a golf tournament. This is problem 010 from csplib.
*
* Note that "Modeling and Programming with Gecode" uses this example
* as a case study.
*
* \ingroup Example
*
*/
class Golf : public Script {
public:
/// Model variants
enum {
MODEL_PLAIN, ///< A simple model
MODEL_SYMMETRY ///< Model with symmetry breaking
};
/// Propagation
enum {
PROP_SET, ///< Propagation of pair play amount using set variables
PROP_INT, ///< Propagation of pair play amount using int variables and distinct
PROP_MIXED, ///< Propagation of pair play amount using both set and int variables
};
int g; ///< Number of groups in a week
int s; ///< Number of players in a group
int w; ///< Number of weeks
/// The sets representing the groups
SetVarArray groups;
/// Actual model
Golf(const GolfOptions& opt)
: Script(opt),
g(opt.g()), s(opt.s()), w(opt.w()),
groups(*this,g*w,IntSet::empty,0,g*s-1,
static_cast<unsigned int>(s),static_cast<unsigned int>(s)) {
Matrix<SetVarArray> schedule(groups,g,w);
// Groups in one week must be disjoint
SetVar allPlayers(*this, 0,g*s-1, 0,g*s-1);
for (int i=0; i<w; i++)
rel(*this, setdunion(schedule.row(i)) == allPlayers);
// No two golfers play in the same group more than once
if (opt.propagation() == PROP_SET || opt.propagation() == PROP_MIXED) {
// Cardinality of intersection between two groups is at most one
for (int i=0; i<groups.size()-1; i++)
for (int j=i+1; j<groups.size(); j++)
rel(*this, cardinality(groups[i] & groups[j]) <= 1);
}
if (opt.propagation() == PROP_INT || opt.propagation() == PROP_MIXED) {
// Set up table mapping from pairs (p1,p2) (where p1<p2) of players to
// unique integer identifiers
int playerCount = g * s;
TupleSet ts(3);
int pairCount=0;
for (int p1=0; p1<playerCount-1; p1++)
for (int p2=p1+1; p2<playerCount; p2++)
ts.add({p1, p2, pairCount++});
ts.finalize();
// Collect pairs of golfers into pairs
IntVarArgs pairs;
for (int i=0; i<groups.size()-1; i++) {
// Channel sorted will ensure that for i<j, group[i]<group[j],
// ensuring that the tuple set has a valid mapping.
IntVarArgs group(*this, s, 0, playerCount-1);
channelSorted(*this, group, groups[i]);
// Collect all pairs in current group
for (int p1=0; p1<group.size()-1; ++p1) {
for (int p2=p1+1; p2<group.size(); ++p2) {
IntVar pair(*this, 0, pairCount);
IntVarArgs args;
args << group[p1] << group[p2] << pair;
extensional(*this, args, ts);
pairs << pair;
}
}
}
// All pairs of golfers (using the unique identifiers) must be different
distinct(*this, pairs, opt.ipl());
}
if (opt.model() == MODEL_SYMMETRY) {
/*
* Redundant constraints and static symmetry breaking from
* "Solving Kirkman's Schoolgirl Problem in a Few Seconds"
* Nicolas Barnier, Pascal Brisset, Constraints, 10, 7-21, 2005
*
*/
// Redundant constraint:
// in each week, one player plays in only one group
for (int j=0; j<w; j++) {
for (int p=0; p < g*s; p++) {
BoolVarArgs b(g);
for (int i=0; i<g; i++)
b[i] = expr(*this, (singleton(p) <= schedule(i,j)));
linear(*this, b, IRT_EQ, 1);
}
}
// Symmetry breaking: order groups
for (int j=0; j<w; j++) {
IntVarArgs m(g);
for (int i=0; i<g; i++)
m[i] = expr(*this, min(schedule(i,j)));
rel(*this, m, IRT_LE);
}
// Symmetry breaking: order weeks
// minElem(group(w,0)\{0}) < minElem(group(w+1,0)\{0})
{
IntVarArgs m(w);
for (int i=0; i<w; i++)
m[i] = expr(*this, min(schedule(0,i)-IntSet(0,0)));
rel(*this, m, IRT_LE);
}
// Symmetry breaking: value symmetry of player numbers
precede(*this, groups, IntArgs::create(groups.size(),0));
}
branch(*this, groups, SET_VAR_MIN_MIN(), SET_VAL_MIN_INC());
}
/// Print solution
virtual void
print(std::ostream& os) const {
os << "Tournament plan" << std::endl;
Matrix<SetVarArray> schedule(groups,g,w);
for (int j=0; j<w; j++) {
os << "Week " << j << ": " << std::endl << " ";
os << schedule.row(j) << std::endl;
}
}
/// Constructor for copying \a s
Golf(Golf& s) : Script(s), g(s.g), s(s.s), w(s.w) {
groups.update(*this, s.groups);
}
/// Copy during cloning
virtual Space*
copy(void) {
return new Golf(*this);
}
};
/** \brief Main-function
* \relates Golf
*/
int
main(int argc, char* argv[]) {
GolfOptions opt;
opt.model(Golf::MODEL_PLAIN);
opt.model(Golf::MODEL_PLAIN, "none", "no symmetry breaking");
opt.model(Golf::MODEL_SYMMETRY, "symmetry", "static symmetry breaking");
opt.propagation(Golf::PROP_SET);
opt.propagation(Golf::PROP_SET, "set", "Use set intersection cardinality for pair play constraints");
opt.propagation(Golf::PROP_INT, "int", "Use integer distinct for pair play constraints");
opt.propagation(Golf::PROP_MIXED, "mixed", "Use set interesection cardinality and integer distinct for pair play constraints");
opt.ipl(IPL_DOM);
opt.solutions(1);
opt.parse(argc,argv);
Script::run<Golf,DFS,GolfOptions>(opt);
return 0;
}
// STATISTICS: example-any