33 #ifndef BASETRANSPOSE_H_
34 #define BASETRANSPOSE_H_
36 #include <permlib/predicate/pointwise_stabilizer_predicate.h>
37 #include <permlib/generator/generator.h>
39 #include <boost/scoped_ptr.hpp>
40 #include <boost/iterator/indirect_iterator.hpp>
41 #include <boost/next_prior.hpp>
49 template<
class PERM,
class TRANS>
69 typedef std::list<typename PERM::ptr> PERMlist;
85 template<
class PERM,
class TRANS>
87 : m_statScheierGeneratorsConsidered(0), m_statNewGenerators(0)
90 template<
class PERM,
class TRANS>
92 std::vector<dom_int> &B = bsgs.B;
93 std::vector<TRANS> &U = bsgs.U;
102 std::swap(B[i], B[i+1]);
107 unsigned int targetTransversalSize = U[i+1].size() * U[i].size();
111 U_i.orbit(B[i], S_i);
112 targetTransversalSize /= U_i.size();
114 m_statScheierGeneratorsConsidered = 0;
115 m_statNewGenerators = 0;
116 TRANS U_i1(U[i+1].n());
117 U_i1.orbit(B[i+1], S_i1);
118 boost::scoped_ptr<Generator<PERM> > generator(setupGenerator(bsgs, i, S_i, U_i));
119 BOOST_ASSERT(generator != 0);
121 while (U_i1.size() < targetTransversalSize) {
122 bool newGeneratorFound =
false;
123 while (generator->hasNext()) {
124 PERM g = generator->next();
125 ++m_statScheierGeneratorsConsidered;
126 boost::indirect_iterator<typename PERMlist::iterator> sBegin(S_i1.begin()), sEnd(S_i1.end());
127 if (!U_i1.contains(g / B[i+1]) && std::find(sBegin, sEnd, g) == sEnd) {
129 boost::shared_ptr<PERM> gen(
new PERM(g));
130 S_i1.push_front(gen);
131 ++m_statNewGenerators;
132 U_i1.orbitUpdate(B[i+1], S_i1, gen);
133 newGeneratorFound =
true;
137 if (!newGeneratorFound)
141 BOOST_ASSERT(U_i1.size() >= targetTransversalSize);
143 bsgs.S.insert(bsgs.S.end(), S_i1.begin(), boost::next(S_i1.begin(), m_statNewGenerators));
150 #endif // -- BASETRANSPOSE_H_