permlib  0.2.6
Library for permutation computations
 All Classes Functions Variables Typedefs Enumerations Friends
include/permlib/invariant/linear_form_list.h
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 LINEAR_FORM_LIST_H_
00034 #define LINEAR_FORM_LIST_H_
00035 
00036 #include <boost/cstdint.hpp>
00037 #include <boost/dynamic_bitset.hpp>
00038 
00039 namespace permlib {
00040 
00042 typedef boost::dynamic_bitset<> LinearForm;
00043 
00045 template<class PERM>
00046 struct LinearFormAction {
00048         LinearForm operator()(const PERM &p, const LinearForm& set) const {
00049                 LinearForm ret(set.size());
00050                 for (unsigned int i = 0; i < ret.size(); ++i) {
00051                         if (set[i])
00052                                 ret.set(p / i, 1);
00053                 }
00054                 return ret;
00055         }
00056 };
00057 
00058 
00060 
00064 class LinearFormList {
00065 public:
00067 
00075         template<typename Z>
00076         Z evaluate(const LinearForm& l, bool moduloPrime = true) const;
00077         
00079         void add(const LinearForm& l) { m_forms.push_back(l); }
00081         unsigned long size() const { return m_forms.size(); }
00082 private:
00083         std::list<LinearForm> m_forms;
00084 };
00085 
00086 template<typename Z>
00087 Z LinearFormList::evaluate(const LinearForm& l, bool moduloPrime) const {
00088         Z result(1);
00089         BOOST_FOREACH(const LinearForm& form, m_forms) {
00090                 BOOST_ASSERT(form.size() == l.size());
00091                 
00092                 LinearForm merge(form);
00093                 merge &= l;
00094                 const Z value(merge.count());
00095                 if (value == 0) {
00096                         return 0;
00097                 }
00098                 result *= value;
00099                 if (moduloPrime)
00100                         result %= 0xFFFFFFFBUL;
00101         }
00102         return result;
00103 }
00104 
00105 }
00106 
00107 #endif // LINEAR_FORM_LIST_H_