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kpeter (Peter Kovacs)
kpeter@inf.elte.hu
Minor improvements in CostScaling (#417)
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1 file changed with 44 insertions and 32 deletions:
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... ...
@@ -575,18 +575,25 @@
575 575
      return *this;
576 576
    }
577 577

	
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    /// \brief Reset all the parameters that have been given before.
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    /// \brief Reset the internal data structures and all the parameters
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    /// that have been given before.
579 580
    ///
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    /// This function resets all the paramaters that have been given
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    /// before using functions \ref lowerMap(), \ref upperMap(),
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    /// \ref costMap(), \ref supplyMap(), \ref stSupply().
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    /// This function resets the internal data structures and all the
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    /// paramaters that have been given before using functions \ref lowerMap(),
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    /// \ref upperMap(), \ref costMap(), \ref supplyMap(), \ref stSupply().
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    ///
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    /// It is useful for multiple run() calls. If this function is not
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    /// used, all the parameters given before are kept for the next
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    /// \ref run() call.
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    /// However, the underlying digraph must not be modified after this
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    /// class have been constructed, since it copies and extends the graph.
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    /// It is useful for multiple \ref run() calls. By default, all the given
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    /// parameters are kept for the next \ref run() call, unless
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    /// \ref resetParams() or \ref reset() is used.
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    /// If the underlying digraph was also modified after the construction
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    /// of the class or the last \ref reset() call, then the \ref reset()
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    /// function must be used, otherwise \ref resetParams() is sufficient.
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    ///
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    /// See \ref resetParams() for examples.
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    ///
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    /// \return <tt>(*this)</tt>
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    ///
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    /// \see resetParams(), run()
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    CostScaling& reset() {
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      // Resize vectors
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      _node_num = countNodes(_graph);
... ...
@@ -890,14 +897,6 @@
890 897
        }
891 898
      }
892 899

	
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      return OPTIMAL;
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    }
895

	
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    // Execute the algorithm and transform the results
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    void start(Method method) {
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      // Maximum path length for partial augment
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      const int MAX_PATH_LENGTH = 4;
900

	
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      // Initialize data structures for buckets
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      _max_rank = _alpha * _res_node_num;
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      _buckets.resize(_max_rank);
... ...
@@ -905,7 +904,13 @@
905 904
      _bucket_prev.resize(_res_node_num + 1);
906 905
      _rank.resize(_res_node_num + 1);
907 906

	
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      // Execute the algorithm
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      return OPTIMAL;
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    }
909

	
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    // Execute the algorithm and transform the results
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    void start(Method method) {
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      const int MAX_PARTIAL_PATH_LENGTH = 4;
913

	
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      switch (method) {
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        case PUSH:
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          startPush();
... ...
@@ -914,7 +919,7 @@
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          startAugment(_res_node_num - 1);
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          break;
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        case PARTIAL_AUGMENT:
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          startAugment(MAX_PATH_LENGTH);
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          startAugment(MAX_PARTIAL_PATH_LENGTH);
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          break;
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      }
920 925

	
... ...
@@ -951,9 +956,10 @@
951 956
        int last_out = _first_out[u+1];
952 957
        LargeCost pi_u = _pi[u];
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        for (int a = _first_out[u]; a != last_out; ++a) {
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          Value delta = _res_cap[a];
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          if (delta > 0) {
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          int v = _target[a];
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          if (_res_cap[a] > 0 && _cost[a] + pi_u - _pi[v] < 0) {
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            Value delta = _res_cap[a];
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            if (_cost[a] + pi_u - _pi[v] < 0) {
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            _excess[u] -= delta;
958 964
            _excess[v] += delta;
959 965
            _res_cap[a] = 0;
... ...
@@ -961,6 +967,7 @@
961 967
          }
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        }
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      }
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      }
964 971

	
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      // Find active nodes (i.e. nodes with positive excess)
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      for (int u = 0; u != _res_node_num; ++u) {
... ...
@@ -1001,25 +1008,27 @@
1001 1008

	
1002 1009
    // Global potential update heuristic
1003 1010
    void globalUpdate() {
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      int bucket_end = _root + 1;
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      const int bucket_end = _root + 1;
1005 1012

	
1006 1013
      // Initialize buckets
1007 1014
      for (int r = 0; r != _max_rank; ++r) {
1008 1015
        _buckets[r] = bucket_end;
1009 1016
      }
1010 1017
      Value total_excess = 0;
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      int b0 = bucket_end;
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      for (int i = 0; i != _res_node_num; ++i) {
1012 1020
        if (_excess[i] < 0) {
1013 1021
          _rank[i] = 0;
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          _bucket_next[i] = _buckets[0];
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          _bucket_prev[_buckets[0]] = i;
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          _buckets[0] = i;
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          _bucket_next[i] = b0;
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          _bucket_prev[b0] = i;
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          b0 = i;
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        } else {
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          total_excess += _excess[i];
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          _rank[i] = _max_rank;
1020 1028
        }
1021 1029
      }
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      if (total_excess == 0) return;
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      _buckets[0] = b0;
1023 1032

	
1024 1033
      // Search the buckets
1025 1034
      int r = 0;
... ...
@@ -1041,8 +1050,9 @@
1041 1050
                // Compute the new rank of v
1042 1051
                LargeCost nrc = (_cost[ra] + _pi[v] - pi_u) / _epsilon;
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                int new_rank_v = old_rank_v;
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                if (nrc < LargeCost(_max_rank))
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                  new_rank_v = r + 1 + int(nrc);
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                if (nrc < LargeCost(_max_rank)) {
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                  new_rank_v = r + 1 + static_cast<int>(nrc);
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                }
1046 1056

	
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                // Change the rank of v
1048 1058
                if (new_rank_v < old_rank_v) {
... ...
@@ -1054,14 +1064,16 @@
1054 1064
                    if (_buckets[old_rank_v] == v) {
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                      _buckets[old_rank_v] = _bucket_next[v];
1056 1066
                    } else {
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                      _bucket_next[_bucket_prev[v]] = _bucket_next[v];
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                      _bucket_prev[_bucket_next[v]] = _bucket_prev[v];
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                      int pv = _bucket_prev[v], nv = _bucket_next[v];
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                      _bucket_next[pv] = nv;
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                      _bucket_prev[nv] = pv;
1059 1070
                    }
1060 1071
                  }
1061 1072

	
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                  // Insert v to its new bucket
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                  _bucket_next[v] = _buckets[new_rank_v];
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                  _bucket_prev[_buckets[new_rank_v]] = v;
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                  // Insert v into its new bucket
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                  int nv = _buckets[new_rank_v];
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                  _bucket_next[v] = nv;
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                  _bucket_prev[nv] = v;
1065 1077
                  _buckets[new_rank_v] = v;
1066 1078
                }
1067 1079
              }
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