permlib  0.2.9
Library for permutation computations
vector_stabilizer_search.h
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31 
32 
33 #ifndef PARTITION_VECTOR_STABILIZER_SEARCH_H_
34 #define PARTITION_VECTOR_STABILIZER_SEARCH_H_
35 
36 #include <permlib/search/partition/r_base.h>
37 #include <permlib/predicate/vector_stabilizer_predicate.h>
38 #include <permlib/search/partition/set_stabilize_refinement.h>
39 #include <permlib/search/partition/refinement_family.h>
40 
41 namespace permlib {
42 namespace partition {
43 
45 template<class BSGSIN,class TRANSRET>
46 class VectorStabilizerSearch : public RBase<BSGSIN,TRANSRET> {
47 public:
48  typedef typename RBase<BSGSIN,TRANSRET>::PERM PERM;
49 
51 
55  VectorStabilizerSearch(const BSGSIN& bsgs, unsigned int pruningLevelDCM);
56 
58 
64  template<class InputIterator>
65  void construct(InputIterator begin, InputIterator end, unsigned int maxEntries);
66 protected:
67  virtual unsigned int processNewFixPoints(const Partition& pi, unsigned int backtrackCount);
68 private:
69  std::vector<unsigned int> toStab;
70  unsigned int m_maxEntries;
71 };
72 
73 template<class BSGSIN,class TRANSRET>
74 VectorStabilizerSearch<BSGSIN,TRANSRET>::VectorStabilizerSearch(const BSGSIN& bsgs, unsigned int pruningLevelDCM)
75  : RBase<BSGSIN,TRANSRET>(bsgs, pruningLevelDCM)
76 { }
77 
78 template<class BSGSIN,class TRANSRET>
79 template<class InputIterator>
80 void VectorStabilizerSearch<BSGSIN,TRANSRET>::construct(InputIterator begin, InputIterator end, unsigned int maxEntries) {
82  m_maxEntries = maxEntries;
83  toStab.insert(toStab.begin(), begin, end);
84  std::vector<unsigned int> stabC(toStab.size());
85 
86 #ifdef PERMLIB_DEBUGMODE
87  BOOST_FOREACH(const unsigned int v, stabC) {
88  BOOST_ASSERT( v < maxEntries );
89  }
90 #endif
91 
92  // we can ignore the highest entries because these are automatically stabilized
93  // if all other entries are stabilized
94  for (unsigned int c = 0; c < maxEntries - 1; ++c) {
95  unsigned int i = 0;
96  std::vector<unsigned int>::iterator stabIt = toStab.begin(), cIt = stabC.begin();
97  for (; stabIt != toStab.end(); ++stabIt) {
98  BOOST_ASSERT( cIt != stabC.end() );
99  if (*stabIt == c)
100  *cIt++ = i;
101  ++i;
102  }
103  SetStabilizeRefinement<PERM> ssr(this->m_bsgs.n, stabC.begin(), cIt);
104  ssr.initializeAndApply(this->m_partition);
105  PERM empty(this->m_bsgs.n);
106  ssr.apply2(this->m_partition2, empty);
107  }
109 }
110 
111 template<class BSGSIN,class TRANSRET>
112 unsigned int VectorStabilizerSearch<BSGSIN,TRANSRET>::processNewFixPoints(const Partition& pi, unsigned int level) {
113  const unsigned int basePos = RBase<BSGSIN,TRANSRET>::processNewFixPoints(pi, level);
114  if (!this->m_limitInitialized) {
115  bool allFound = true;
116  int pos = -1;
117  BOOST_FOREACH(unsigned int alpha, toStab) {
118  ++pos;
119  if (alpha == m_maxEntries - 1)
120  continue;
121  if (std::find(pi.fixPointsBegin(), pi.fixPointsEnd(), static_cast<unsigned int>(pos)) == pi.fixPointsEnd()) {
122  allFound = false;
123  break;
124  }
125  }
126  if (allFound) {
127  this->m_limitLevel = level;
128  this->m_limitBase = basePos;
129  this->m_limitInitialized = true;
130  }
131  }
132  return basePos;
133 }
134 
135 }
136 }
137 
138 #endif // -- PARTITION_VECTOR_STABILIZER_SEARCH_H_
subgroup search for a stabilizer of an integer vector based on partition backtracking ...
Definition: vector_stabilizer_search.h:46
bool initializeAndApply(Partition &pi)
applies (left-)refinement to partition and initializes refinement for future use in R-base ...
Definition: refinement.h:136
vector_t::const_iterator fixPointsEnd() const
iterator to the end of fix points
Definition: partition.h:167
concrete -refinements for set stabilization
Definition: set_stabilize_refinement.h:50
partition
Definition: partition.h:48
virtual unsigned int processNewFixPoints(const Partition &pi, unsigned int backtrackCount)
callback when a new fix point appears during R-base construction
Definition: vector_stabilizer_search.h:112
VectorStabilizerSearch(const BSGSIN &bsgs, unsigned int pruningLevelDCM)
constructor
Definition: vector_stabilizer_search.h:74
void construct(InputIterator begin, InputIterator end, unsigned int maxEntries)
initializes search
Definition: vector_stabilizer_search.h:80
R-base for partition backtracking.
Definition: r_base.h:56
void construct(SubgroupPredicate< PERM > *pred, RefinementFamily< PERM > *predRefinement)
constructs an R-base for given predicate and refinement family
Definition: r_base.h:115
virtual unsigned int processNewFixPoints(const Partition &pi, unsigned int level)
callback when a new fix point appears during R-base construction
Definition: r_base.h:197
vector_t::const_iterator fixPointsBegin() const
iterator to the begin of fix points
Definition: partition.h:164
Definition: abstract_bsgs.h:49
predicate for the subgroup that stabilizes a given integer vector
Definition: vector_stabilizer_predicate.h:44