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 BASECHANGE_H_ 00034 #define BASECHANGE_H_ 00035 00036 #include <permlib/predicate/pointwise_stabilizer_predicate.h> 00037 00038 namespace permlib { 00039 00041 00045 template<class PERM,class TRANS> 00046 class BaseChange { 00047 public: 00049 BaseChange() : m_statTranspositions(0), m_statScheierGeneratorsConsidered(0) {} 00050 00052 mutable unsigned int m_statTranspositions; 00053 00055 mutable unsigned int m_statScheierGeneratorsConsidered; 00056 protected: 00058 00063 bool isRedundant(const BSGSCore<PERM,TRANS>& bsgs, unsigned int baseTargetPos, unsigned long alpha) const; 00064 }; 00065 00066 template<class PERM,class TRANS> 00067 bool BaseChange<PERM,TRANS>::isRedundant(const BSGSCore<PERM,TRANS>& bsgs, unsigned int baseTargetPos, unsigned long alpha) const { 00068 bool redundant = true; 00069 const PointwiseStabilizerPredicate<PERM> stab_i(bsgs.B.begin(), bsgs.B.begin() + baseTargetPos); 00070 BOOST_FOREACH(const typename PERM::ptr& g, bsgs.S) { 00071 if (!stab_i(g)) 00072 continue; 00073 if (*g / alpha != alpha) { 00074 redundant = false; 00075 break; 00076 } 00077 } 00078 00079 #ifdef PERMLIB_DEBUG_OUTPUT 00080 if (redundant) { 00081 std::cout << "skip redundant " << (alpha+1) << std::endl; 00082 print_iterable(bsgs.B.begin(), bsgs.B.begin() + baseTargetPos, 1, " redundant for"); 00083 } else { 00084 std::cout << "look for " << (alpha+1) << " at position " << baseTargetPos << std::endl; 00085 } 00086 #endif 00087 00088 return redundant; 00089 } 00090 00091 } 00092 00093 #endif // -- BASECHANGE_H_