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deba@inf.elte.hu
deba@inf.elte.hu
Unify DynArcLookUp interface (ticket #127)
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1 file changed with 71 insertions and 101 deletions:
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Ignore white space 6 line context
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@@ -29,7 +29,7 @@
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///\brief LEMON core utilities.
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///
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///This header file contains core utilities for LEMON.
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///It is automatically included by all graph types, therefore it usually 
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///It is automatically included by all graph types, therefore it usually
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///do not have to be included directly.
34 34

	
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namespace lemon {
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@@ -1171,11 +1171,11 @@
1171 1171
  ///Dynamic arc look up between given endpoints.
1172 1172

	
1173 1173
  ///Using this class, you can find an arc in a digraph from a given
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  ///source to a given target in amortized time <em>O(log d)</em>,
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  ///source to a given target in amortized time <em>O(log</em>d<em>)</em>,
1175 1175
  ///where <em>d</em> is the out-degree of the source node.
1176 1176
  ///
1177 1177
  ///It is possible to find \e all parallel arcs between two nodes with
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  ///the \c findFirst() and \c findNext() members.
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  ///the \c operator() member.
1179 1179
  ///
1180 1180
  ///See the \ref ArcLookUp and \ref AllArcLookUp classes if your
1181 1181
  ///digraph is not changed so frequently.
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@@ -1423,8 +1423,8 @@
1423 1423
    void refresh() {
1424 1424
      for(NodeIt n(_g);n!=INVALID;++n) {
1425 1425
        std::vector<Arc> v;
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        for(OutArcIt e(_g,n);e!=INVALID;++e) v.push_back(e);
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        if(v.size()) {
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        for(OutArcIt a(_g,n);a!=INVALID;++a) v.push_back(a);
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        if (!v.empty()) {
1428 1428
          std::sort(v.begin(),v.end(),ArcLess(_g));
1429 1429
          Arc head = refreshRec(v,0,v.size()-1);
1430 1430
          _head.set(n, head);
... ...
@@ -1506,113 +1506,83 @@
1506 1506

	
1507 1507
    ///Find an arc between two nodes.
1508 1508

	
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    ///Find an arc between two nodes in time <em>O(</em>log<em>d)</em>, where
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    /// <em>d</em> is the number of outgoing arcs of \c s.
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    ///Find an arc between two nodes.
1511 1510
    ///\param s The source node
1512 1511
    ///\param t The target node
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    ///\return An arc from \c s to \c t if there exists,
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    ///\ref INVALID otherwise.
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    Arc operator()(Node s, Node t) const
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    {
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      Arc a = _head[s];
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      if (a == INVALID) return INVALID;
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      while (true) {
1520
        if (_g.target(a) == t) {
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    ///\param p The previous arc between \c s and \c t. It it is INVALID or
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    ///not given, the operator finds the first appropriate arc.
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    ///\return An arc from \c s to \c t after \c p or
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    ///\ref INVALID if there is no more.
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    ///
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    ///For example, you can count the number of arcs from \c u to \c v in the
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    ///following way.
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    ///\code
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    ///DynArcLookUp<ListDigraph> ae(g);
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    ///...
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    ///int n=0;
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    ///for(Arc e=ae(u,v);e!=INVALID;e=ae(u,v,e)) n++;
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    ///\endcode
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    ///
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    ///Finding the arcs take at most <em>O(</em>log<em>d)</em>
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    ///amortized time, specifically, the time complexity of the lookups
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    ///is equal to the optimal search tree implementation for the
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    ///current query distribution in a constant factor.
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    ///
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    ///\note This is a dynamic data structure, therefore the data
1532
    ///structure is updated after each graph alteration. However,
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    ///theoretically this data structure is faster than \c ArcLookUp
1534
    ///or AllEdgeLookup, but it often provides worse performance than
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    ///them.
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    ///
1537
    Arc operator()(Node s, Node t, Arc p = INVALID) const  {
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      if (p == INVALID) {
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        Arc a = _head[s];
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        if (a == INVALID) return INVALID;
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        Arc r = INVALID;
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        while (true) {
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          if (_g.target(a) < t) {
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            if (_right[a] == INVALID) {
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              const_cast<DynArcLookUp&>(*this).splay(a);
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              return r;
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            } else {
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              a = _right[a];
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            }
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          } else {
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            if (_g.target(a) == t) {
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              r = a;
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            }
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            if (_left[a] == INVALID) {
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              const_cast<DynArcLookUp&>(*this).splay(a);
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              return r;
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            } else {
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              a = _left[a];
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            }
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          }
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        }
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      } else {
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        Arc a = p;
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        if (_right[a] != INVALID) {
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          a = _right[a];
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          while (_left[a] != INVALID) {
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            a = _left[a];
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          }
1521 1569
          const_cast<DynArcLookUp&>(*this).splay(a);
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          return a;
1523
        } else if (t < _g.target(a)) {
1524
          if (_left[a] == INVALID) {
1525
            const_cast<DynArcLookUp&>(*this).splay(a);
1570
        } else {
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          while (_parent[a] != INVALID && _right[_parent[a]] ==  a) {
1572
            a = _parent[a];
1573
          }
1574
          if (_parent[a] == INVALID) {
1526 1575
            return INVALID;
1527 1576
          } else {
1528
            a = _left[a];
1529
          }
1530
        } else  {
1531
          if (_right[a] == INVALID) {
1577
            a = _parent[a];
1532 1578
            const_cast<DynArcLookUp&>(*this).splay(a);
1533
            return INVALID;
1534
          } else {
1535
            a = _right[a];
1536 1579
          }
1537 1580
        }
1581
        if (_g.target(a) == t) return a;
1582
        else return INVALID;
1538 1583
      }
1539 1584
    }
1540 1585

	
1541
    ///Find the first arc between two nodes.
1542

	
1543
    ///Find the first arc between two nodes in time
1544
    /// <em>O(</em>log<em>d)</em>, where <em>d</em> is the number of
1545
    /// outgoing arcs of \c s.
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    ///\param s The source node
1547
    ///\param t The target node
1548
    ///\return An arc from \c s to \c t if there exists, \ref INVALID
1549
    /// otherwise.
1550
    Arc findFirst(Node s, Node t) const
1551
    {
1552
      Arc a = _head[s];
1553
      if (a == INVALID) return INVALID;
1554
      Arc r = INVALID;
1555
      while (true) {
1556
        if (_g.target(a) < t) {
1557
          if (_right[a] == INVALID) {
1558
            const_cast<DynArcLookUp&>(*this).splay(a);
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            return r;
1560
          } else {
1561
            a = _right[a];
1562
          }
1563
        } else {
1564
          if (_g.target(a) == t) {
1565
            r = a;
1566
          }
1567
          if (_left[a] == INVALID) {
1568
            const_cast<DynArcLookUp&>(*this).splay(a);
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            return r;
1570
          } else {
1571
            a = _left[a];
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          }
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        }
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      }
1575
    }
1576

	
1577
    ///Find the next arc between two nodes.
1578

	
1579
    ///Find the next arc between two nodes in time
1580
    /// <em>O(</em>log<em>d)</em>, where <em>d</em> is the number of
1581
    /// outgoing arcs of \c s.
1582
    ///\param s The source node
1583
    ///\param t The target node
1584
    ///\return An arc from \c s to \c t if there exists, \ref INVALID
1585
    /// otherwise.
1586

	
1587
    ///\note If \c e is not the result of the previous \c findFirst()
1588
    ///operation then the amorized time bound can not be guaranteed.
1589
#ifdef DOXYGEN
1590
    Arc findNext(Node s, Node t, Arc a) const
1591
#else
1592
    Arc findNext(Node, Node t, Arc a) const
1593
#endif
1594
    {
1595
      if (_right[a] != INVALID) {
1596
        a = _right[a];
1597
        while (_left[a] != INVALID) {
1598
          a = _left[a];
1599
        }
1600
        const_cast<DynArcLookUp&>(*this).splay(a);
1601
      } else {
1602
        while (_parent[a] != INVALID && _right[_parent[a]] ==  a) {
1603
          a = _parent[a];
1604
        }
1605
        if (_parent[a] == INVALID) {
1606
          return INVALID;
1607
        } else {
1608
          a = _parent[a];
1609
          const_cast<DynArcLookUp&>(*this).splay(a);
1610
        }
1611
      }
1612
      if (_g.target(a) == t) return a;
1613
      else return INVALID;
1614
    }
1615

	
1616 1586
  };
1617 1587

	
1618 1588
  ///Fast arc look up between given endpoints.
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