permlib  0.2.9
Library for permutation computations
group_sorter.h
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31 
32 
33 #ifndef GROUPSORTER_H
34 #define GROUPSORTER_H
35 
36 #include <boost/foreach.hpp>
37 
38 namespace permlib {
39 
41 template <class PERM>
42 class GroupSorter : public std::binary_function<PERM, PERM, bool>{
43 public:
45 
50  template <class InputIterator>
51  GroupSorter(unsigned int size, InputIterator begin, InputIterator end) :
52  // initialize m_size elements with value m_size
53  m_order(size, size),
54  m_base(begin, end)
55  {
56  InputIterator it;
57  unsigned int i = 0;
58  // base elements first
59  for (it = begin; it != end; ++it) {
60  m_order[*it] = ++i;
61  }
62  }
63 
65  bool operator() (PERM a, PERM b) const {
66  BOOST_FOREACH(unsigned long beta, m_base) {
67  if (m_order[a / beta] < m_order[b / beta])
68  return true;
69  }
70  return false;
71  }
72 private:
73  std::vector<unsigned long> m_order;
74  std::vector<unsigned long> m_base;
75 };
76 
77 }
78 
79 #endif // -- GROUPSORTER_H
GroupSorter(unsigned int size, InputIterator begin, InputIterator end)
constructor
Definition: group_sorter.h:51
bool operator()(PERM a, PERM b) const
true iff a < b
Definition: group_sorter.h:65
A sorter that sorts a sequence of permutations with respect to a ordering induced by a base...
Definition: group_sorter.h:42
Definition: abstract_bsgs.h:49