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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- *//* * Main authors: * Patrick Pekczynski <pekczynski@ps.uni-sb.de> * Mikael Lagerkvist <lagerkvist@gecode.org> * Christian Schulte <schulte@gecode.org> * * Copyright: * Patrick Pekczynski, 2004 * Mikael Lagerkvist, 2006 * 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>
using namespace Gecode;
/** * \brief Options taking two additional parameters * * \relates LangfordNumber */class LangfordNumberOptions : public Options {public: int k, n; /// Parameters to be given on the command line /// Initialize options for example with name \a s LangfordNumberOptions(const char* s, int k0, int n0) : Options(s), k(k0), 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; n = atoi(argv[1]); k = atoi(argv[2]); } /// Print help message virtual void help(void) { Options::help(); std::cerr << "\t(unsigned int) default: " << n << std::endl << "\t\tparameter n" << std::endl << "\t(unsigned int) default: " << k << std::endl << "\t\tparameter k" << std::endl; }};
/** * \brief %Example: Langford's number problem * * See problem 24 at http://www.csplib.org/. * * \ingroup Example */class LangfordNumber : public Script {protected: int k, n; ///< Problem parameters IntVarArray y; ///< Sequence variables
public: /// Propagation to use for model enum { PROP_REIFIED, ///< Use reified constraints PROP_EXTENSIONAL, ///< Use extensional constraints PROP_EXTENSIONAL_CHANNEL ///< Use extensional and channel constraints }; /// Construct model LangfordNumber(const LangfordNumberOptions& opt) : Script(opt), k(opt.k), n(opt.n), y(*this,k*n,1,n) {
switch (opt.propagation()) { case PROP_REIFIED: { // Position of values in sequence IntVarArgs pv(*this,k*n,0,k*n-1); Matrix<IntVarArgs> p(pv,n,k);
/* * The occurences of v in the Langford sequence are v numbers apart. * * Let \#(i, v) denote the position of the i-th occurence of * value v in the Langford Sequence. Then * * \f$ \forall i, j \in \{1, \dots, k\}, i \neq j: * \forall v \in \{1, \dots, n\}: \#(i, v) + (v + 1) = \#(j, v)\f$ * */ for (int i=0; i<n; i++) for (int j=0; j<k-1; j++) rel(*this, p(i,j)+i+2 == p(i,j+1));
distinct(*this, pv, opt.ipl());
// Channel positions <-> values for (int i=0; i<n; i++) for (int j=0; j<k; j++) element(*this, y, p(i,j), i+1); } break; case PROP_EXTENSIONAL: { IntArgs a(n-1); for (int v=2; v<=n; v++) a[v-2]=v; for (int v=1; v<=n; v++) { // Construct regular expression for all symbols but v if (v > 1) a[v-2]=v-1; REG ra(a), rv(v); extensional(*this, y, *ra+rv+(ra(v,v)+rv)(k-1,k-1)+*ra); } } break; case PROP_EXTENSIONAL_CHANNEL: { // Boolean variables for channeling BoolVarArgs bv(*this,k*n*n,0,1); Matrix<BoolVarArgs> b(bv,k*n,n);
// Post channel constraints for (int i=0; i<n*k; i++) channel(*this, b.col(i), y[i], 1);
// For placing two numbers three steps apart, we construct the // regular expression 0*100010*, and apply it to the projection of // the sequence on the value. REG r0(0), r1(1); for (int v=1; v<=n; v++) extensional(*this, b.row(v-1), *r0 + r1 + (r0(v,v) + r1)(k-1,k-1) + *r0); } break; }
// Symmetry breaking rel(*this, y[0], IRT_LE, y[n*k-1]);
// Branching branch(*this, y, INT_VAR_SIZE_MIN(), INT_VAL_MAX()); }
/// Print solution virtual void print(std::ostream& os) const { os << "\t" << y << std::endl; }
/// Constructor for cloning \a l LangfordNumber(LangfordNumber& l) : Script(l), k(l.k), n(l.n) { y.update(*this, l.y);
} /// Copy during cloning virtual Space* copy(void) { return new LangfordNumber(*this); }};
/** \brief Main-function * \relates LangfordNumber */intmain(int argc, char* argv[]) { LangfordNumberOptions opt("Langford Numbers",3,9); opt.ipl(IPL_DOM); opt.propagation(LangfordNumber::PROP_EXTENSIONAL_CHANNEL); opt.propagation(LangfordNumber::PROP_REIFIED, "reified"); opt.propagation(LangfordNumber::PROP_EXTENSIONAL, "extensional"); opt.propagation(LangfordNumber::PROP_EXTENSIONAL_CHANNEL, "extensional-channel"); opt.parse(argc, argv); if (opt.k < 1) { std::cerr << "k must be at least 1!" << std::endl; return 1; } if (opt.k > opt.n) { std::cerr << "n must be at least k!" << std::endl; return 1; } Script::run<LangfordNumber,DFS,LangfordNumberOptions>(opt); return 0;}
// STATISTICS: example-any