permlib  0.2.9
Library for permutation computations
known_bsgs_construction.h
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31 
32 
33 #ifndef KNOWNBSGSCONSTRUCTION_H_
34 #define KNOWNBSGSCONSTRUCTION_H_
35 
36 #include <permlib/construct/base_construction.h>
37 #include <permlib/bsgs.h>
38 
39 namespace permlib {
40 
42 template <class PERM, class TRANS>
43 class KnownBSGSConstruction : public BaseConstruction<PERM, TRANS> {
44 public:
46 
49  KnownBSGSConstruction(unsigned int n);
50 
52 
58  template <class ForwardIterator, class InputIterator>
59  BSGS<PERM, TRANS> construct(ForwardIterator generatorsBegin, ForwardIterator generatorsEnd, InputIterator knownBaseBegin, InputIterator knownBaseEnd) const;
60 };
61 
62 //
63 // ---- IMPLEMENTATION
64 //
65 
66 template <class PERM, class TRANS>
68  : BaseConstruction<PERM, TRANS>(n)
69 { }
70 
71 
72 template <class PERM, class TRANS>
73 template <class ForwardIterator, class InputIterator>
75  ::construct(ForwardIterator generatorsBegin, ForwardIterator generatorsEnd, InputIterator knownBaseBegin, InputIterator knownBaseEnd) const
76 {
77  const unsigned int &n = this->m_n;
78  BSGS<PERM, TRANS> ret(n);
79  std::vector<std::list<typename PERM::ptr> > S;
80  this->setup(generatorsBegin, generatorsEnd, knownBaseBegin, knownBaseEnd, ret, S);
81  BOOST_ASSERT( S.size() > 0 );
82  // the strong generating set of the group is the
83  // stabilizer of the empty set of the given generators
84  ret.S.insert(ret.S.end(), S[0].begin(), S[0].end());
85  return ret;
86 }
87 
88 }
89 
90 #endif // -- KNOWNBSGSCONSTRUCTION_H_
BSGS construction from a known base and strong generating set.
Definition: known_bsgs_construction.h:43
KnownBSGSConstruction(unsigned int n)
constructor
Definition: known_bsgs_construction.h:67
base class for BSGS construction algorithms
Definition: base_construction.h:46
BSGS< PERM, TRANS > construct(ForwardIterator generatorsBegin, ForwardIterator generatorsEnd, InputIterator knownBaseBegin, InputIterator knownBaseEnd) const
sets up a BSGS data structure for a known base and strong generating set
Definition: known_bsgs_construction.h:75
Represents a base and strong generating set (BSGS)
Definition: bsgs.h:58
PERMlist S
strong generating set
Definition: bsgs_core.h:57
Definition: abstract_bsgs.h:49