virtual-ranges-inter.hpp
Go to the documentation of this file.
00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */ 00002 /* 00003 * Main authors: 00004 * Christian Schulte <schulte@gecode.org> 00005 * 00006 * Copyright: 00007 * Christian Schulte, 2004 00008 * 00009 * Last modified: 00010 * $Date: 2008-12-05 16:43:57 +0100 (Fri, 05 Dec 2008) $ by $Author: schulte $ 00011 * $Revision: 7989 $ 00012 * 00013 * This file is part of Gecode, the generic constraint 00014 * development environment: 00015 * http://www.gecode.org 00016 * 00017 * Permission is hereby granted, free of charge, to any person obtaining 00018 * a copy of this software and associated documentation files (the 00019 * "Software"), to deal in the Software without restriction, including 00020 * without limitation the rights to use, copy, modify, merge, publish, 00021 * distribute, sublicense, and/or sell copies of the Software, and to 00022 * permit persons to whom the Software is furnished to do so, subject to 00023 * the following conditions: 00024 * 00025 * The above copyright notice and this permission notice shall be 00026 * included in all copies or substantial portions of the Software. 00027 * 00028 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 00029 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 00030 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 00031 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 00032 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 00033 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 00034 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 00035 * 00036 */ 00037 00038 #include <algorithm> 00039 00040 namespace Gecode { namespace Iter { namespace Ranges { namespace Virt { 00041 00047 class Inter : public MinMax, public Iterator { 00048 private: 00049 Inter(const Inter&); 00050 protected: 00052 Iterator* i; 00054 Iterator* j; 00055 public: 00057 00058 00059 Inter(void); 00061 Inter(Iterator* i, Iterator* j); 00063 ~Inter(void); 00065 00067 00068 00069 virtual int min(void) const; 00071 virtual int max(void) const; 00073 virtual unsigned int width(void) const; 00075 00077 00078 00079 virtual void operator ++(void); 00081 virtual bool operator ()(void); 00083 }; 00084 00085 00091 class NaryInter : public MinMax, public Iterator { 00092 private: 00093 NaryInter(const NaryInter&); 00094 protected: 00096 Iterator** is; 00098 int n; 00099 public: 00101 00102 00103 NaryInter(void); 00105 NaryInter(Iterator** i, int n); 00107 00109 00110 00111 virtual int min(void) const; 00113 virtual int max(void) const; 00115 virtual unsigned int width(void) const; 00117 00119 00120 00121 void operator ++(void); 00123 virtual bool operator ()(void); 00125 }; 00126 00127 00128 /* 00129 * Binary intersection 00130 * 00131 */ 00132 00133 inline void 00134 Inter::operator ++(void) { 00135 if (!(*i)() || !(*j)()) goto done; 00136 do { 00137 while ((*i)() && (i->max() < j->min())) ++(*i); 00138 if (!(*i)()) goto done; 00139 while ((*j)() && (j->max() < i->min())) ++(*j); 00140 if (!(*j)()) goto done; 00141 } while (i->max() < j->min()); 00142 // Now the intervals overlap: consume the smaller interval 00143 ma = std::min(i->max(),j->max()); 00144 mi = std::max(i->min(),j->min()); 00145 if (i->max() < j->max()) ++(*i); else ++(*j); 00146 return; 00147 done: 00148 finish(); 00149 } 00150 00151 forceinline 00152 Inter::Inter(void) {} 00153 00154 forceinline 00155 Inter::Inter(Iterator* i0, Iterator* j0) 00156 : i(i0), j(j0) { 00157 operator ++(); 00158 } 00159 00160 forceinline 00161 Inter::~Inter(void) { delete i; delete j; } 00162 00163 forceinline bool 00164 Inter::operator ()(void) { return MinMax::operator ()(); } 00165 00166 forceinline int 00167 Inter::min(void) const { return MinMax::min(); } 00168 00169 forceinline int 00170 Inter::max(void) const { return MinMax::max(); } 00171 00172 forceinline unsigned int 00173 Inter::width(void) const { return MinMax::width(); } 00174 00175 /* 00176 * Nary intersection 00177 * 00178 */ 00179 00180 inline void 00181 NaryInter::operator ++(void) { 00182 // The next interval to be returned must have a hole 00183 // between it and the previously returned range. 00184 mi = ma+2; 00185 ma = is[0]->max(); 00186 // Intersect with all other intervals 00187 restart: 00188 for (int i = n; i--;) { 00189 // Skip intervals that are too small 00190 while ((*(is[i]))() && (is[i]->max() < mi)) 00191 ++(*(is[i])); 00192 if (!(*(is[i]))()) 00193 goto done; 00194 00195 if (is[i]->min() > ma) { 00196 mi=is[i]->min(); 00197 ma=is[i]->max(); 00198 goto restart; 00199 } 00200 // Now the intervals overlap 00201 if (mi < is[i]->min()) 00202 mi = is[i]->min(); 00203 if (ma > is[i]->max()) { 00204 ma = is[i]->max(); 00205 } 00206 } 00207 return; 00208 done: 00209 finish(); 00210 } 00211 00212 forceinline 00213 NaryInter::NaryInter(void) {} 00214 00215 inline 00216 NaryInter::NaryInter(Iterator** is0, int n0) 00217 : is(is0), n(n0) { 00218 if (!(*(is[0]))()) { 00219 finish(); 00220 } else { 00221 ma=is[0]->min()-2; 00222 operator ++(); 00223 } 00224 } 00225 00226 forceinline bool 00227 NaryInter::operator ()(void) { return MinMax::operator ()(); } 00228 00229 forceinline int 00230 NaryInter::min(void) const { return MinMax::min(); } 00231 00232 forceinline int 00233 NaryInter::max(void) const { return MinMax::max(); } 00234 00235 forceinline unsigned int 00236 NaryInter::width(void) const { return MinMax::width(); } 00237 00238 }}}} 00239 00240 // STATISTICS: iter-any 00241