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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Patrick Pekczynski <pekczynski@ps.uni-sb.de>
*
* Contributing authors:
* Christian Schulte <schulte@gecode.org>
*
* Copyright:
* Patrick Pekczynski, 2004
* Christian Schulte, 2007
*
* 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>
#include <algorithm>
#include <iomanip>
using namespace Gecode;
/// Entry in round robin schedule
class Play {
public:
int h; ///< home team
int a; ///< away team
int g; ///< game number
/// Default constructor
Play(void) : h(0), a(0), g(0) {}
};
/// Round robin schedule
class RRS {
protected:
/// Number of teams
const int teams;
/// Play information
Play* plays;
/// Return number of weeks
int weeks(void) const {
return teams-1;
}
/// Return number of periods
int periods(void) const {
return teams/2;
}
/// Game number for game between home team \a h and away team \a a
int gn(int h, int a) const {
return teams*(h-1) + a;
}
/// Play for period \a p and week \a w
Play& play(int p, int w) {
return plays[p*weeks() + w];
}
public:
/**
* \brief Build a feasible schedule
*
* The games of the first week are fixed as:
* \f$ \langle 1,2 \rangle \cup
* \{\langle p + 2, t - p + 1\rangle | p \geq 1\}\f$. \n
* The remaining games are computed by transforming a game
* \f$ \langle h, a, g \rangle \f$ from the previous week
* in a new game \f$ \langle h', a'\rangle \f$, where: \n
* \f$ h' = \left\{
* \begin{tabular}{l c l}
* 1 & & if $h = 1$ \\
* 2 & & if $h = t$ \\
* $h + 1$ & & otherwise
* \end{tabular}\right.
* \f$ and
* \f$ a' = \left\{
* \begin{tabular}{l c l}
* 2 & & if $h = t$ \\
* a + 1 & & otherwise
* \end{tabular}\right.
* \f$
*
*
*/
RRS(int t) : teams(t), plays(new Play[periods()*weeks()]) {
// Determine the first game (week 0 period 0)
play(0,0).h = 1;
play(0,0).a = 2;
play(0,0).g = 2;
// Determine the other games of the first week
for (int p=1; p<periods(); p++) {
play(p,0).h = (p + 1) + 1;
play(p,0).a = teams - (p + 1 - 2);
play(p,0).g = gn(play(p,0).h,play(p,0).a);
}
// Compute the games for the subsequent weeks
for (int w=1; w<weeks(); w++) {
for (int p=0; p<periods(); p++) {
if (play(p,w-1).h == teams)
play(p,w).h = 2;
else if (play(p,w-1).h == 1)
play(p,w).h = 1;
else
play(p,w).h = play(p,w-1).h + 1;
if (play(p,w-1).a == teams)
play(p,w).a = 2;
else
play(p,w).a = play(p,w-1).a + 1;
// maintain symmetry for (h,a): h < a
if (play(p,w).h > play(p,w).a)
std::swap(play(p,w).h,play(p,w).a);
play(p,w).g = gn(play(p,w).h,play(p,w).a);
}
}
}
/// Home, away, and game information
void hag(int w, IntArgs& h, IntArgs& a, IntArgs& g) {
for (int p=0; p<periods(); p++) {
h[p] = play(p,w).h;
a[p] = play(p,w).a;
g[p] = play(p,w).g;
}
}
/// Delete schedule
~RRS(void) {
delete [] plays;
}
};
/**
* \brief %Example: %Sports league scheduling
*
* -# There are \f$ t \f$ teams (\f$ t \f$ even).
* -# The season lasts \f$ t - 1 \f$ weeks.
* -# Each game between two different teams occurs exactly once.
* -# Every team plays one game in each week of the season.
* -# There are \f$ \displaystyle\frac{t}{2} \f$ periods and each week
* every period is scheduled for one game.
* -# No team plays more than twice in the same period over
* the course of the season.
*
* See also problem 26 at http://www.csplib.org/.
*
* \ingroup Example
*/
class SportsLeague : public Script {
protected:
const int teams; ///< number of teams
IntVarArray home; ///< home teams
IntVarArray away; ///< away teams
IntVarArray game; ///< game numbers
/// Return number of weeks
int weeks(void) const {
return teams-1;
}
/// Return number of periods
int periods(void) const {
return teams/2;
}
/// Home team in period \a p and week \a w
IntVar& h(int p, int w) {
return home[p*teams + w];
}
/// Home team in period \a p and week \a w
const IntVar& h(int p, int w) const {
return home[p*teams + w];
}
/// Away team in period \a p and week \a w
IntVar& a(int p, int w) {
return away[p*teams + w];
}
/// Away team in period \a p and week \a w
const IntVar& a(int p, int w) const {
return away[p*teams + w];
}
/// Return game number for game in period \a p and week \a w
IntVar& g(int p, int w) {
return game[p*weeks() + w];
}
/// Return game number for game in period \a p and week \a w
const IntVar& g(int p, int w) const {
return game[p*weeks() + w];
}
public:
/// Setup model
SportsLeague(const SizeOptions& opt) :
Script(opt),
teams(opt.size()),
home(*this, periods() * teams, 1, weeks()),
away(*this, periods() * teams, 2, weeks()+1),
game(*this, weeks()*periods(), 2, teams*weeks())
{
// Initialize round robin schedule
RRS r(teams);
// Domain for gamenumber of period
for (int w=0; w<weeks(); w++) {
IntArgs rh(periods()), ra(periods()), rg(periods());
IntVarArgs n(*this,periods(),0,periods()-1);
distinct(*this, n, opt.ipl());
r.hag(w,rh,ra,rg);
for (int p=0; p<periods(); p++) {
element(*this, rh, n[p], h(p,w));
element(*this, ra, n[p], a(p,w));
element(*this, rg, n[p], g(p,w));
}
}
/// (h,a) and (a,h) are the same game, focus on home (that is, h<a)
for (int p=0; p<periods(); p++)
for (int w=0; w<teams; w++)
rel(*this, h(p,w), IRT_LE, a(p,w));
// Home teams in first week are ordered
{
IntVarArgs h0(periods());
for (int p=0; p<periods(); p++)
h0[p] = h(p,0);
rel(*this, h0, IRT_LE);
}
// Fix first pair
rel(*this, h(0,0), IRT_EQ, 1);
rel(*this, a(0,0), IRT_EQ, 2);
/// Column constraint: each team occurs exactly once
for (int w=0; w<teams; w++) {
IntVarArgs c(teams);
for (int p=0; p<periods(); p++) {
c[2*p] = h(p,w); c[2*p+1] = a(p,w);
}
distinct(*this, c, opt.ipl());
}
/// Row constraint: no team appears more than twice
for (int p=0; p<periods(); p++) {
IntVarArgs r(2*teams);
for (int t=0; t<teams; t++) {
r[2*t] = h(p,t);
r[2*t+1] = a(p,t);
}
IntArgs values(teams);
for (int i=1; i<=teams; i++)
values[i-1] = i;
count(*this, r, IntSet(2,2), values, opt.ipl());
}
// Redundant constraint
for (int p=0; p<periods(); p++)
for (int w=0; w<weeks(); w ++)
rel(*this, teams * h(p,w) + a(p,w) - g(p,w) == teams);
distinct(*this, game, opt.ipl());
branch(*this, game, INT_VAR_NONE(), INT_VAL_SPLIT_MIN());
}
/// Constructor for cloning \a s
SportsLeague(SportsLeague& s)
: Script(s), teams(s.teams) {
home.update(*this, s.home);
away.update(*this, s.away);
game.update(*this, s.game);
}
/// Copy during cloning
virtual Space*
copy(void) {
return new SportsLeague(*this);
}
/// Print solution
virtual void print(std::ostream& os) const {
// print period index
os << "\t ";
for (int p=0; p<periods(); p++) {
os << "P[";
os.width(2);
os << p << "] ";
}
os << std::endl;
// print entries
for (int w=0; w<weeks(); w++) {
os << "\tW[";
os.width(2);
os << w+1 << "]: ";
for (int p=0; p<periods(); p++) {
os.width(2);
os << h(p,w).val() << '-';
os.width(2);
os << a(p,w).val() << " ";
}
os << std::endl;
}
}
};
/** \brief Main-function
* \relates SportsLeague
*/
int
main(int argc, char* argv[]) {
SizeOptions opt("Sports League Scheduling");
opt.ipl(IPL_DOM);
opt.size(18);
opt.parse(argc,argv);
if (opt.size() < 5) {
std::cerr<< "No Solution for less than 5 teams!" << std::endl;
return 1;
}
if (opt.size() % 2 != 0) {
std::cerr << "Number of teams has to be even!" << std::endl;
return 1;
}
Script::run<SportsLeague, DFS,SizeOptions>(opt);
return 0;
}
// STATISTICS: example-any