GetFEM  5.4.3
dal_bit_vector.h
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4  Copyright (C) 1995-2020 Yves Renard
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30 ===========================================================================*/
31 
32 
33 #ifndef DAL_BIT_VECTOR_H__
34 #define DAL_BIT_VECTOR_H__
35 
36 
37 /** @file dal_bit_vector.h
38  @author Yves Renard <[email protected]>
39  @date June 01, 1995.
40  @brief Provide a dynamic bit container.
41 
42  Provide a dynamic bit container, which can also be considered as a
43  set of integers.
44 
45  As a convention, the default value of a bit is false. The main
46  member functions are dal::bit_vector::is_in,
47  dal::bit_vector::add, dal::bit_vector::sup. Iterate over the
48  bit_vector with dal::bv_visitor
49 */
50 
51 #include "dal_basic.h"
52 #include <limits.h>
53 #include <bitset>
54 #include <iterator>
55 #include <algorithm>
56 
57 namespace dal {
58 
59  typedef unsigned int bit_support;
60  static const bit_support WD_BIT = bit_support(CHAR_BIT*sizeof(bit_support));
61  static const bit_support WD_MASK = WD_BIT - 1;
62  typedef dynamic_array<bit_support, 4> bit_container;
63 
64  class bit_vector;
65 
66  struct APIDECL bit_reference {
67  typedef size_t size_type;
68 
69  bit_support* p;
70  bit_support mask;
71  size_type ind;
72  bit_vector* bv;
73 
74  bit_reference(bit_support* x, bit_support m, size_type y, bit_vector* z)
75  { p = x; ind = y; bv = z; mask = m; }
76  bit_reference(void) {}
77  operator bool(void) const { return (*p & mask) != 0; }
78  bit_reference& operator = (bool x);
79  bit_reference& operator=(const bit_reference& x)
80  { return *this = bool(x); }
81  bool operator==(const bit_reference& x) const
82  { return bool(*this) == bool(x); }
83  bool operator<(const bit_reference& x) const
84  { return bool(*this) < bool(x); }
85  bool operator>(const bit_reference& x) const
86  { return bool(*this) > bool(x); }
87  bool operator>=(const bit_reference& x) const
88  { return bool(*this) >= bool(x); }
89  void flip(void) { if (bool(*this)) *this = false; else *this = true; }
90  };
91 
92  struct APIDECL bit_iterator {
93  typedef bool value_type;
94  typedef bit_reference reference;
95  typedef bit_reference* pointer;
96  typedef size_t size_type;
97  typedef ptrdiff_t difference_type;
98  typedef std::random_access_iterator_tag iterator_category;
99 
100  size_type ind;
101  bit_support mask;
102  bit_container::iterator p;
103  bit_vector* bv;
104 
105  inline void bump_up()
106  { ind++; if (!(mask <<= 1)) { ++p; mask = 1;} }
107  inline void bump_down()
108  { ind--; if (!(mask >>= 1)) { --p; mask = 1; mask <<= WD_MASK; } }
109 
110  bit_iterator(void) {}
111  bit_iterator(bit_vector &b, size_type i);
112  reference operator*() const
113  { return reference(&(*p), mask, ind, bv); }
114  bit_iterator& operator++() { bump_up(); return *this; }
115  bit_iterator operator++(int)
116  { bit_iterator tmp=*this; bump_up(); return tmp; }
117  bit_iterator& operator--() { bump_down(); return *this; }
118  bit_iterator operator--(int)
119  { bit_iterator tmp = *this; bump_down(); return tmp; }
120  bit_iterator& operator+=(difference_type i);
121  bit_iterator& operator-=(difference_type i)
122  { *this += -i; return *this; }
123  bit_iterator operator+(difference_type i) const
124  { bit_iterator tmp = *this; return tmp += i; }
125  bit_iterator operator-(difference_type i) const
126  { bit_iterator tmp = *this; return tmp -= i; }
127  difference_type operator-(bit_iterator x) const { return ind - x.ind; }
128  reference operator[](difference_type i) { return *(*this + i); }
129  size_type index(void) const { return ind; }
130  bool operator==(const bit_iterator& x) const { return ind == x.ind; }
131  bool operator!=(const bit_iterator& x) const { return ind != x.ind; }
132  bool operator<(bit_iterator x) const { return ind < x.ind; }
133  bool operator>(bit_iterator x) const { return ind > x.ind; }
134  bool operator>=(bit_iterator x) const { return ind >= x.ind; }
135  };
136 
137  struct APIDECL bit_const_iterator {
138  typedef bool value_type;
139  typedef bool reference;
140  typedef const bool* pointer;
141  typedef size_t size_type;
142  typedef ptrdiff_t difference_type;
143  typedef std::random_access_iterator_tag iterator_category;
144 
145  size_type ind;
146  bit_support mask;
147  bit_container::const_iterator p;
148  const bit_vector* bv;
149 
150  inline void bump_up()
151  { ind++; if (!(mask <<= 1)) { ++p; mask = 1;} }
152  inline void bump_down()
153  { ind--; if (!(mask >>= 1)) { --p; mask = 1; mask <<= WD_MASK; } }
154 
155  bit_const_iterator() {}
156  bit_const_iterator(const bit_vector &b, size_type i);
157  bit_const_iterator(const bit_iterator& x)
158  : ind(x.ind), mask(x.mask), p(x.p), bv(x.bv) {}
159  reference operator*() const { return (*p & mask) != 0; }
160  bit_const_iterator& operator++() { bump_up(); return *this; }
161  bit_const_iterator operator++(int)
162  { bit_const_iterator tmp = *this; bump_up(); return tmp; }
163  bit_const_iterator& operator--() { bump_down(); return *this; }
164  bit_const_iterator operator--(int)
165  { bit_const_iterator tmp = *this; bump_down(); return tmp; }
166  bit_const_iterator& operator+=(difference_type i);
167  bit_const_iterator& operator-=(difference_type i)
168  { *this += -i; return *this; }
169  bit_const_iterator operator+(difference_type i) const
170  { bit_const_iterator tmp = *this; return tmp += i; }
171  bit_const_iterator operator-(difference_type i) const
172  { bit_const_iterator tmp = *this; return tmp -= i; }
173  difference_type operator-(bit_const_iterator x) const { return ind-x.ind; }
174  reference operator[](difference_type i) { return *(*this + i); }
175  size_type index(void) const { return ind; }
176  bool operator==(const bit_const_iterator& x) const { return ind == x.ind; }
177  bool operator!=(const bit_const_iterator& x) const { return ind != x.ind; }
178  bool operator<(bit_const_iterator x) const { return ind < x.ind; }
179  bool operator>(bit_const_iterator x) const { return ind > x.ind; }
180  bool operator>=(bit_const_iterator x) const { return ind >= x.ind; }
181  };
182 
183  ///Dynamic bit container.
184  class APIDECL bit_vector : public bit_container {
185  public :
186 
187  typedef bool value_type;
188  typedef size_t size_type;
189  typedef ptrdiff_t difference_type;
190  typedef bool const_reference;
191  typedef const bool* const_pointer;
192  typedef bit_reference reference;
193  typedef bit_reference* pointer;
194  typedef bit_iterator iterator;
195  typedef bit_const_iterator const_iterator;
196 
197  protected :
198 
199  mutable size_type ifirst_true, ilast_true;
200  mutable size_type ifirst_false, ilast_false;
201  mutable size_type icard;
202  mutable bool icard_valid;
203 
204  void fill_false(size_type i1, size_type i2);
205 
206  public :
207 
208  void change_for_true(size_type i) {
209  ifirst_true = std::min(ifirst_true, i);
210  ilast_true = std::max(ilast_true, i);
211  ++icard;
212  }
213  void change_for_false(size_type i) {
214  ifirst_false = std::min(ifirst_false, i);
215  ilast_false = std::max(ilast_false, i);
216  --icard;
217  }
218 
219  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
220  typedef std::reverse_iterator<iterator> reverse_iterator;
221  size_type size(void) const { return std::max(ilast_true, ilast_false)+1;}
222 
223  iterator begin(void) { return iterator(*this, 0); }
224  const_iterator begin(void) const { return const_iterator(*this, 0); }
225  iterator end(void) { return iterator(*this, size()); }
226  const_iterator end(void) const { return const_iterator(*this, size()); }
227 
228  reverse_iterator rbegin(void) { return reverse_iterator(end()); }
229  const_reverse_iterator rbegin(void) const
230  { return const_reverse_iterator(end()); }
231  reverse_iterator rend(void) { return reverse_iterator(begin()); }
232  const_reverse_iterator rend(void) const
233  { return const_reverse_iterator(begin()); }
234 
235  size_type capacity(void) const
236  { return bit_container::capacity() * WD_BIT; }
237  size_type max_size(void) const { return (size_type(-1)); }
238  // bool empty(void) const { return card() == 0; } /* ?? */
239  reference front(void) { return *begin(); }
240  const_reference front(void) const { return *begin(); }
241  reference back(void) { return *(end() - 1); }
242  const_reference back(void) const { return *(end() - 1); }
243 
244 
245  const_reference operator [](size_type ii) const
246  { return (ii >= size()) ? false : *const_iterator(*this, ii); }
247  reference operator [](size_type ii)
248  { if (ii >= size()) fill_false(size(),ii); return *iterator(*this, ii);}
249 
250  void swap(bit_vector &da);
251 
252  void clear(void) {
253  icard = 0; icard_valid = true;
254  ifirst_false = ilast_false = ifirst_true = ilast_true = 0;
255  fill_false(0,0);
256  }
257  void swap(size_type i1, size_type i2) {
258  if (i1 != i2) {
259  reference r1 = (*this)[i1], r2 = (*this)[i2];
260  bool tmp = r1; r1 = r2; r2 = tmp;
261  }
262  }
263  size_type memsize(void) const {
264  return bit_container::memsize() + sizeof(bit_vector)
265  - sizeof(bit_container);
266  }
267  size_type card(void) const;
268  /// index of first non-zero entry (size_type(-1) for an empty bit_vector)
269  size_type first_true(void) const;
270  /// index of first zero entry (size_type(0) for an empty bit_vector)
271  size_type first_false(void) const;
272  /// index of last non-zero entry (size_type(-1) for an empty bit_vector)
273  size_type last_true(void) const;
274  /// index of last zero entry (size_type(0) for an empty bit_vector)
275  size_type last_false(void) const;
276  /// remove all elements found in bv
277  bit_vector &setminus(const bit_vector &bv);
278  bit_vector &operator |=(const bit_vector &bv);
279  bit_vector &operator &=(const bit_vector &bv);
280 
281  bit_vector operator |(const bit_vector &bv) const
282  { bit_vector r(*this); r |= bv; return r; }
283  bit_vector operator &(const bit_vector &bv) const
284  { bit_vector r(*this); r &= bv; return r; }
285  bool operator ==(const bit_vector &bv) const;
286  bool operator !=(const bit_vector &bv) const
287  { return !((*this) == bv); }
288 
289  bit_vector(void) { clear(); }
290  template <size_t N> bit_vector(const std::bitset<N> &bs) {
291  clear();
292  for (size_type i=0; i < bs.size(); ++i) { if (bs[i]) add(i); }
293  }
294 
295  /// merges the integer values of the supplied container into the bit_vector
296  template <typename ICONT> dal::bit_vector& merge_from(const ICONT& c) {
297  for (typename ICONT::const_iterator it = c.begin(); it != c.end(); ++it)
298  add(*it);
299  return *this;
300  }
301  /** merges the integer values of the supplied iterator range into
302  * the bit_vector */
303  template <typename IT> dal::bit_vector& merge_from(IT b, IT e) {
304  while (b != e) { add(*b++); }
305  return *this;
306  }
307  /** return true if the supplied bit_vector is a subset of the current
308  * bit_vector */
309  bool contains(const dal::bit_vector &other) const;
310 
311  public :
312  /// return true if (*this)[i] == true
313  bool is_in(size_type i) const {
314  if (i < ifirst_true || i > ilast_true) return false;
315  else return (((*(const bit_container*)(this))[i / WD_BIT]) &
316  (bit_support(1) << (i & WD_MASK))) ? true : false; }
317  void add(size_type i) { (*this)[i] = true; }
318  /** set the interval [i .. i+nb-1] to true */
319  void add(size_type i, size_type nb);
320  void sup(size_type i) { (*this)[i] = false; } /* deprecated ...*/
321  void del(size_type i) { (*this)[i] = false; }
322  /** set the interval [i .. i+nb-1] to false */
323  void sup(size_type i, size_type nb); /* deprecated ...*/
324  void del(size_type i, size_type nb);
325  int first(void) const { return (card() == 0) ? -1 : int(first_true()); }
326  int last(void) const { return (card() == 0) ? -1 : int(last_true()); }
327  inline int take_first(void)
328  { int res = first(); if (res >= 0) sup(res); return res; }
329  inline int take_last(void)
330  { int res = last(); if (res >= 0) sup(res); return res; }
331  };
332 
333  /**
334  if you are only interested in indexes of true values of a bit_vector
335  (i.e. if you use it as an int set), use bv_visitor instead of
336  bit_vector::const_iterator (much faster)
337 
338  example:
339  @code
340  for (bv_visitor i(v); !i.finished(); ++i) {
341  .... (use i as an unsigned int)
342  }
343  @endcode
344  CAUTION: use bv_visitor_c instead of bv_visitor if the class bv_visitor
345  need to store a copy of the bit_vector
346  (if the original is destroyed just after the creation...)
347  */
348  class APIDECL bv_visitor {
349  typedef dal::bit_vector::size_type size_type;
350  bit_container::const_iterator it;
351  size_type ilast,ind;
352  bit_support v;
353  public:
354  bv_visitor(const dal::bit_vector& b) :
355  it(((const bit_container&)b).begin()+b.first()/WD_BIT),
356  ilast(b.last()+1), ind(b.first()), v(0) {
357  if (ind < ilast) { v = *it; v >>= (ind&WD_MASK); }
358  }
359  bool finished() const { return ind >= ilast; }
360  bool operator++();
361  operator size_type() const { return ind; }
362  };
363 
364  /**
365  bv_visitor with local copy of the bit_vector
366  */
367  class APIDECL bv_visitor_c {
368  bit_vector bv;
369  bv_visitor v; // no inheritance since v must be init after bv
370  public:
371  bv_visitor_c(const dal::bit_vector& b) : bv(b), v(bv) {}
372  bool finished() const { return v.finished(); }
373  bool operator++() { return ++v; }
374  operator dal::bit_vector::size_type() const
375  { return dal::bit_vector::size_type(v); }
376  };
377 
378  /// extract index of first entry in the bit_vector
379  inline int APIDECL &operator << (int &i, bit_vector &s)
380  { i = s.take_first(); return i; }
381  inline const int APIDECL &operator >> (const int &i, bit_vector &s)
382  { s.add(i); return i; }
383 
384  inline size_t APIDECL &operator << (size_t &i, bit_vector &s)
385  { i = s.take_first(); return i; }
386  inline const size_t &operator >> (const size_t &i, bit_vector &s)
387  { s.add(i); return i; }
388 
389  std::ostream APIDECL &operator <<(std::ostream &o, const bit_vector &s);
390 
391  /**Iterator class for bv_iterable and bv_iterable_c.*/
392  template<typename ITERABLE_BV>
393  class const_bv_iterator
394  {
395  typedef dal::bit_vector::size_type size_type;
396 
397  public:
398 
399  typedef std::forward_iterator_tag iterator_category;
400  typedef size_type value_type;
401  typedef size_type difference_type;
402  typedef size_type* pointer;
403  typedef size_type& reference;
404 
405  const_bv_iterator(const ITERABLE_BV* p_iterable, size_type pos)
406  : p_iterable_(const_cast<ITERABLE_BV*>(p_iterable)), pos_(pos)
407  {}
408 
409  bool operator!= (const const_bv_iterator &other) const{
410  return pos_ < other.pos_;
411  }
412 
413  size_type operator *() const{
414  return size_type(*p_iterable_);
415  }
416 
417  //difference of iterators
418  size_type operator-(const const_bv_iterator &other) const{
419  if (pos_ == other.pos_) return 0;
420 
421  auto &vector_this = p_iterable_->v_;
422  auto &vector_other = other.p_iterable_->v_;
423  bv_visitor v_this(vector_this), v_other(vector_other);
424  while (v_this < pos_) ++v_this;
425  while (v_other < other.pos_) ++v_other;
426  auto &v = (pos_ < other.pos_) ? v_this : v_other;
427  auto &v_end = (pos_ >= other.pos_) ? v_this : v_other;
428 
429  size_type count = 0;
430  while(v < v_end) { ++v; ++count;}
431  return count;
432  }
433 
434  const const_bv_iterator &operator++(){
435  ++*p_iterable_;
436  pos_ = *p_iterable_;
437  return *this;
438  }
439 
440  private:
441  ITERABLE_BV *p_iterable_;
442  size_type pos_;
443  };
444 
445 
446  /**
447  Wrapper class to make bit_vector iterable on true values.
448  It enables the use of c++11 range-based loop feature.
449  example:
450  @code
451  for (auto i : bv_iterable(bit_vector)) {
452  .... //(use i as an unsigned int)
453  }
454  */
455  class bv_iterable
456  {
457  public:
458  bv_iterable(const bit_vector &v) : v_(v), visitor_(v){}
459 
460  const_bv_iterator<bv_iterable> begin() const;
461  const_bv_iterator<bv_iterable> end() const;
462  inline bool operator++(){return ++visitor_;};
463  inline operator dal::bit_vector::size_type() const{return visitor_;};
464 
465  private:
466  const bit_vector& v_;
467  bv_visitor visitor_;
468  friend class const_bv_iterator<bv_iterable>;
469  };
470 
471  /***Same as bv_iterable class except the bit_vector is copied locally.*/
472  class bv_iterable_c
473  {
474  public:
475  bv_iterable_c(const bit_vector &v) : v_(v), visitor_(v_){}
476  const_bv_iterator<bv_iterable_c> begin() const;
477  const_bv_iterator<bv_iterable_c> end() const;
478  inline bool operator++(){return ++visitor_;};
479  inline operator dal::bit_vector::size_type() const{return visitor_;};
480 
481  private:
482  bit_vector v_;
483  bv_visitor visitor_;
484  friend class const_bv_iterator<bv_iterable_c>;
485  };
486 
487 }
488 
489 #endif /* DAL_BIT_VECTOR_H__ */
dal_basic.h
Dynamic array class.
gmm::clear
void clear(L &l)
clear (fill with zeros) a vector or matrix.
Definition: gmm_blas.h:59
gmm::add
void add(const L1 &l1, L2 &l2)
*‍/
Definition: gmm_blas.h:1277
bgeot::operator-
rational_fraction< T > operator-(const polynomial< T > &P, const rational_fraction< T > &Q)
Subtract Q from P.
Definition: bgeot_poly.h:756
bgeot::operator+
rational_fraction< T > operator+(const polynomial< T > &P, const rational_fraction< T > &Q)
Add Q to P.
Definition: bgeot_poly.h:749
bgeot::operator==
bool operator==(const pconvex_structure &p1, const pconvex_structure &p2)
Stored objects must be compared by keys, because there is a possibility that they are duplicated in s...
Definition: bgeot_convex_structure.cc:111
bgeot::size_type
size_t size_type
used as the common size type in the library
Definition: bgeot_poly.h:49
dal
Dynamic Array Library.
Definition: dal_backtrace.cc:29