permlib
0.2.6
Library for permutation computations
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00001 // --------------------------------------------------------------------------- 00002 // 00003 // This file is part of PermLib. 00004 // 00005 // Copyright (c) 2009-2011 Thomas Rehn <thomas@carmen76.de> 00006 // All rights reserved. 00007 // 00008 // Redistribution and use in source and binary forms, with or without 00009 // modification, are permitted provided that the following conditions 00010 // are met: 00011 // 1. Redistributions of source code must retain the above copyright 00012 // notice, this list of conditions and the following disclaimer. 00013 // 2. Redistributions in binary form must reproduce the above copyright 00014 // notice, this list of conditions and the following disclaimer in the 00015 // documentation and/or other materials provided with the distribution. 00016 // 3. The name of the author may not be used to endorse or promote products 00017 // derived from this software without specific prior written permission. 00018 // 00019 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 00020 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00021 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 00022 // IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 00023 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 00024 // NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 00025 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 00026 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00027 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 00028 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00029 // 00030 // --------------------------------------------------------------------------- 00031 00032 00033 #ifndef EXPLICITTRANSVERSAL_H_ 00034 #define EXPLICITTRANSVERSAL_H_ 00035 00036 #include <permlib/transversal/transversal.h> 00037 00038 namespace permlib { 00039 00041 template <class PERM> 00042 class ExplicitTransversal : public Transversal<PERM> { 00043 public: 00045 ExplicitTransversal(unsigned int n); 00046 00047 virtual PERM* at(unsigned long val) const; 00048 virtual bool trivialByDefinition(const PERM& x, unsigned long to) const; 00049 00050 virtual void permute(const PERM& g, const PERM& gInv); 00051 00053 00056 ExplicitTransversal<PERM> clone(const std::map<PERM*,typename PERM::ptr>& generatorChange) const; 00057 00059 static const unsigned int m_statMaxDepth; 00060 protected: 00061 virtual void registerMove(unsigned long from, unsigned long to, const typename PERM::ptr &p); 00062 }; 00063 00064 // 00065 // ---- IMPLEMENTATION 00066 // 00067 00068 template <class PERM> 00069 const unsigned int ExplicitTransversal<PERM>::m_statMaxDepth = 1; 00070 00071 template <class PERM> 00072 ExplicitTransversal<PERM>::ExplicitTransversal(unsigned int n_) 00073 : Transversal<PERM>(n_) 00074 { } 00075 00076 template <class PERM> 00077 bool ExplicitTransversal<PERM>::trivialByDefinition(const PERM& x, unsigned long to) const { 00078 // we cannot infer this information from the transversal 00079 return false; 00080 } 00081 00082 template <class PERM> 00083 PERM* ExplicitTransversal<PERM>::at(unsigned long val) const { 00084 if (!Transversal<PERM>::m_transversal[val]) 00085 return 0; 00086 return new PERM(*(Transversal<PERM>::m_transversal[val])); 00087 } 00088 00089 template <class PERM> 00090 void ExplicitTransversal<PERM>::registerMove(unsigned long from, unsigned long to, const typename PERM::ptr &p) { 00091 Transversal<PERM>::registerMove(from, to, p); 00092 00093 std::vector<boost::shared_ptr<PERM> > &transversal = Transversal<PERM>::m_transversal; 00094 00095 if (!transversal[from]) 00096 transversal[to] = boost::shared_ptr<PERM>(new PERM(*p)); 00097 else { 00098 transversal[to] = boost::shared_ptr<PERM>(new PERM(*transversal[from])); 00099 (*transversal[to]) *= *p; 00100 } 00101 } 00102 00103 template <class PERM> 00104 void ExplicitTransversal<PERM>::permute(const PERM& g, const PERM& gInv) { 00105 Transversal<PERM>::permute(g, gInv); 00106 BOOST_FOREACH(typename PERM::ptr& p, Transversal<PERM>::m_transversal) { 00107 if (p) { 00108 *p ^= gInv; 00109 *p *= g; 00110 } 00111 } 00112 } 00113 00114 template <class PERM> 00115 ExplicitTransversal<PERM> ExplicitTransversal<PERM>::clone(const std::map<PERM*,typename PERM::ptr>& generatorChange) const { 00116 ExplicitTransversal<PERM> ret(*this); 00117 BOOST_FOREACH(typename PERM::ptr& p, ret.m_transversal) { 00118 if (!p) 00119 continue; 00120 p = boost::shared_ptr<PERM>(new PERM(*p)); 00121 } 00122 return ret; 00123 } 00124 00125 } 00126 00127 #endif // -- EXPLICITTRANSVERSAL_H_