... |
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@@ -33,8 +33,9 @@
|
33 |
33 |
/// Default traits class of Circulation class.
|
34 |
|
/// \tparam GR Digraph type.
|
35 |
|
/// \tparam LM Lower bound capacity map type.
|
36 |
|
/// \tparam UM Upper bound capacity map type.
|
37 |
|
/// \tparam DM Delta map type.
|
|
34 |
///
|
|
35 |
/// \tparam GR Type of the digraph the algorithm runs on.
|
|
36 |
/// \tparam LM The type of the lower bound map.
|
|
37 |
/// \tparam UM The type of the upper bound (capacity) map.
|
|
38 |
/// \tparam SM The type of the supply map.
|
38 |
39 |
template <typename GR, typename LM,
|
39 |
|
typename UM, typename DM>
|
|
40 |
typename UM, typename SM>
|
40 |
41 |
struct CirculationDefaultTraits {
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@@ -44,26 +45,24 @@
|
44 |
45 |
|
45 |
|
/// \brief The type of the map that stores the circulation lower
|
46 |
|
/// bound.
|
|
46 |
/// \brief The type of the lower bound map.
|
47 |
47 |
///
|
48 |
|
/// The type of the map that stores the circulation lower bound.
|
49 |
|
/// It must meet the \ref concepts::ReadMap "ReadMap" concept.
|
50 |
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typedef LM LCapMap;
|
|
48 |
/// The type of the map that stores the lower bounds on the arcs.
|
|
49 |
/// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
|
|
50 |
typedef LM LowerMap;
|
51 |
51 |
|
52 |
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/// \brief The type of the map that stores the circulation upper
|
53 |
|
/// bound.
|
|
52 |
/// \brief The type of the upper bound (capacity) map.
|
54 |
53 |
///
|
55 |
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/// The type of the map that stores the circulation upper bound.
|
56 |
|
/// It must meet the \ref concepts::ReadMap "ReadMap" concept.
|
57 |
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typedef UM UCapMap;
|
|
54 |
/// The type of the map that stores the upper bounds (capacities)
|
|
55 |
/// on the arcs.
|
|
56 |
/// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
|
|
57 |
typedef UM UpperMap;
|
58 |
58 |
|
59 |
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/// \brief The type of the map that stores the lower bound for
|
60 |
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/// the supply of the nodes.
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|
59 |
/// \brief The type of supply map.
|
61 |
60 |
///
|
62 |
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/// The type of the map that stores the lower bound for the supply
|
63 |
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/// of the nodes. It must meet the \ref concepts::ReadMap "ReadMap"
|
64 |
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/// concept.
|
65 |
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typedef DM DeltaMap;
|
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61 |
/// The type of the map that stores the signed supply values of the
|
|
62 |
/// nodes.
|
|
63 |
/// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
|
|
64 |
typedef SM SupplyMap;
|
66 |
65 |
|
67 |
66 |
/// \brief The type of the flow values.
|
68 |
|
typedef typename DeltaMap::Value Value;
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|
67 |
typedef typename SupplyMap::Value Flow;
|
69 |
68 |
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@@ -72,4 +71,5 @@
|
72 |
71 |
/// The type of the map that stores the flow values.
|
73 |
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/// It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
|
74 |
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typedef typename Digraph::template ArcMap<Value> FlowMap;
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|
72 |
/// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap"
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|
73 |
/// concept.
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|
74 |
typedef typename Digraph::template ArcMap<Flow> FlowMap;
|
75 |
75 |
|
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@@ -78,3 +78,3 @@
|
78 |
78 |
/// This function instantiates a \ref FlowMap.
|
79 |
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/// \param digraph The digraph, to which we would like to define
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|
79 |
/// \param digraph The digraph for which we would like to define
|
80 |
80 |
/// the flow map.
|
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@@ -95,3 +95,3 @@
|
95 |
95 |
/// This function instantiates an \ref Elevator.
|
96 |
|
/// \param digraph The digraph, to which we would like to define
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|
96 |
/// \param digraph The digraph for which we would like to define
|
97 |
97 |
/// the elevator.
|
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@@ -105,3 +105,3 @@
|
105 |
105 |
/// The tolerance used by the algorithm to handle inexact computation.
|
106 |
|
typedef lemon::Tolerance<Value> Tolerance;
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|
106 |
typedef lemon::Tolerance<Flow> Tolerance;
|
107 |
107 |
|
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@@ -113,7 +113,8 @@
|
113 |
113 |
\ingroup max_flow
|
114 |
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This class implements a push-relabel algorithm for the network
|
115 |
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circulation problem.
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|
114 |
This class implements a push-relabel algorithm for the \e network
|
|
115 |
\e circulation problem.
|
116 |
116 |
It is to find a feasible circulation when lower and upper bounds
|
117 |
|
are given for the flow values on the arcs and lower bounds
|
118 |
|
are given for the supply values of the nodes.
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|
117 |
are given for the flow values on the arcs and lower bounds are
|
|
118 |
given for the difference between the outgoing and incoming flow
|
|
119 |
at the nodes.
|
119 |
120 |
|
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@@ -121,27 +122,42 @@
|
121 |
122 |
Let \f$G=(V,A)\f$ be a digraph,
|
122 |
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\f$lower, upper: A\rightarrow\mathbf{R}^+_0\f$,
|
123 |
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\f$delta: V\rightarrow\mathbf{R}\f$. Find a feasible circulation
|
124 |
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\f$f: A\rightarrow\mathbf{R}^+_0\f$ so that
|
125 |
|
\f[ \sum_{a\in\delta_{out}(v)} f(a) - \sum_{a\in\delta_{in}(v)} f(a)
|
126 |
|
\geq delta(v) \quad \forall v\in V, \f]
|
127 |
|
\f[ lower(a)\leq f(a) \leq upper(a) \quad \forall a\in A. \f]
|
128 |
|
\note \f$delta(v)\f$ specifies a lower bound for the supply of node
|
129 |
|
\f$v\f$. It can be either positive or negative, however note that
|
130 |
|
\f$\sum_{v\in V}delta(v)\f$ should be zero or negative in order to
|
131 |
|
have a feasible solution.
|
|
123 |
\f$lower, upper: A\rightarrow\mathbf{R}^+_0\f$ denote the lower and
|
|
124 |
upper bounds on the arcs, for which \f$0 \leq lower(uv) \leq upper(uv)\f$
|
|
125 |
holds for all \f$uv\in A\f$, and \f$sup: V\rightarrow\mathbf{R}\f$
|
|
126 |
denotes the signed supply values of the nodes.
|
|
127 |
If \f$sup(u)>0\f$, then \f$u\f$ is a supply node with \f$sup(u)\f$
|
|
128 |
supply, if \f$sup(u)<0\f$, then \f$u\f$ is a demand node with
|
|
129 |
\f$-sup(u)\f$ demand.
|
|
130 |
A feasible circulation is an \f$f: A\rightarrow\mathbf{R}^+_0\f$
|
|
131 |
solution of the following problem.
|
132 |
132 |
|
133 |
|
\note A special case of this problem is when
|
134 |
|
\f$\sum_{v\in V}delta(v) = 0\f$. Then the supply of each node \f$v\f$
|
135 |
|
will be \e equal \e to \f$delta(v)\f$, if a circulation can be found.
|
136 |
|
Thus a feasible solution for the
|
137 |
|
\ref min_cost_flow "minimum cost flow" problem can be calculated
|
138 |
|
in this way.
|
|
133 |
\f[ \sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu)
|
|
134 |
\geq sup(u) \quad \forall u\in V, \f]
|
|
135 |
\f[ lower(uv) \leq f(uv) \leq upper(uv) \quad \forall uv\in A. \f]
|
|
136 |
|
|
137 |
The sum of the supply values, i.e. \f$\sum_{u\in V} sup(u)\f$ must be
|
|
138 |
zero or negative in order to have a feasible solution (since the sum
|
|
139 |
of the expressions on the left-hand side of the inequalities is zero).
|
|
140 |
It means that the total demand must be greater or equal to the total
|
|
141 |
supply and all the supplies have to be carried out from the supply nodes,
|
|
142 |
but there could be demands that are not satisfied.
|
|
143 |
If \f$\sum_{u\in V} sup(u)\f$ is zero, then all the supply/demand
|
|
144 |
constraints have to be satisfied with equality, i.e. all demands
|
|
145 |
have to be satisfied and all supplies have to be used.
|
|
146 |
|
|
147 |
If you need the opposite inequalities in the supply/demand constraints
|
|
148 |
(i.e. the total demand is less than the total supply and all the demands
|
|
149 |
have to be satisfied while there could be supplies that are not used),
|
|
150 |
then you could easily transform the problem to the above form by reversing
|
|
151 |
the direction of the arcs and taking the negative of the supply values
|
|
152 |
(e.g. using \ref ReverseDigraph and \ref NegMap adaptors).
|
|
153 |
|
|
154 |
Note that this algorithm also provides a feasible solution for the
|
|
155 |
\ref min_cost_flow "minimum cost flow problem".
|
139 |
156 |
|
140 |
157 |
\tparam GR The type of the digraph the algorithm runs on.
|
141 |
|
\tparam LM The type of the lower bound capacity map. The default
|
|
158 |
\tparam LM The type of the lower bound map. The default
|
142 |
159 |
map type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>".
|
143 |
|
\tparam UM The type of the upper bound capacity map. The default
|
144 |
|
map type is \c LM.
|
145 |
|
\tparam DM The type of the map that stores the lower bound
|
146 |
|
for the supply of the nodes. The default map type is
|
|
160 |
\tparam UM The type of the upper bound (capacity) map.
|
|
161 |
The default map type is \c LM.
|
|
162 |
\tparam SM The type of the supply map. The default map type is
|
147 |
163 |
\ref concepts::Digraph::NodeMap "GR::NodeMap<UM::Value>".
|
... |
... |
@@ -152,3 +168,3 @@
|
152 |
168 |
typename UM,
|
153 |
|
typename DM,
|
|
169 |
typename SM,
|
154 |
170 |
typename TR >
|
... |
... |
@@ -158,4 +174,4 @@
|
158 |
174 |
typename UM = LM,
|
159 |
|
typename DM = typename GR::template NodeMap<typename UM::Value>,
|
160 |
|
typename TR = CirculationDefaultTraits<GR, LM, UM, DM> >
|
|
175 |
typename SM = typename GR::template NodeMap<typename UM::Value>,
|
|
176 |
typename TR = CirculationDefaultTraits<GR, LM, UM, SM> >
|
161 |
177 |
#endif
|
... |
... |
@@ -169,11 +185,10 @@
|
169 |
185 |
///The type of the flow values.
|
170 |
|
typedef typename Traits::Value Value;
|
|
186 |
typedef typename Traits::Flow Flow;
|
171 |
187 |
|
172 |
|
/// The type of the lower bound capacity map.
|
173 |
|
typedef typename Traits::LCapMap LCapMap;
|
174 |
|
/// The type of the upper bound capacity map.
|
175 |
|
typedef typename Traits::UCapMap UCapMap;
|
176 |
|
/// \brief The type of the map that stores the lower bound for
|
177 |
|
/// the supply of the nodes.
|
178 |
|
typedef typename Traits::DeltaMap DeltaMap;
|
|
188 |
///The type of the lower bound map.
|
|
189 |
typedef typename Traits::LowerMap LowerMap;
|
|
190 |
///The type of the upper bound (capacity) map.
|
|
191 |
typedef typename Traits::UpperMap UpperMap;
|
|
192 |
///The type of the supply map.
|
|
193 |
typedef typename Traits::SupplyMap SupplyMap;
|
179 |
194 |
///The type of the flow map.
|
... |
... |
@@ -193,5 +208,5 @@
|
193 |
208 |
|
194 |
|
const LCapMap *_lo;
|
195 |
|
const UCapMap *_up;
|
196 |
|
const DeltaMap *_delta;
|
|
209 |
const LowerMap *_lo;
|
|
210 |
const UpperMap *_up;
|
|
211 |
const SupplyMap *_supply;
|
197 |
212 |
|
... |
... |
@@ -203,3 +218,3 @@
|
203 |
218 |
|
204 |
|
typedef typename Digraph::template NodeMap<Value> ExcessMap;
|
|
219 |
typedef typename Digraph::template NodeMap<Flow> ExcessMap;
|
205 |
220 |
ExcessMap* _excess;
|
... |
... |
@@ -233,5 +248,5 @@
|
233 |
248 |
struct SetFlowMap
|
234 |
|
: public Circulation<Digraph, LCapMap, UCapMap, DeltaMap,
|
|
249 |
: public Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
|
235 |
250 |
SetFlowMapTraits<_FlowMap> > {
|
236 |
|
typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap,
|
|
251 |
typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
|
237 |
252 |
SetFlowMapTraits<_FlowMap> > Create;
|
... |
... |
@@ -259,5 +274,5 @@
|
259 |
274 |
struct SetElevator
|
260 |
|
: public Circulation<Digraph, LCapMap, UCapMap, DeltaMap,
|
|
275 |
: public Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
|
261 |
276 |
SetElevatorTraits<_Elevator> > {
|
262 |
|
typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap,
|
|
277 |
typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
|
263 |
278 |
SetElevatorTraits<_Elevator> > Create;
|
... |
... |
@@ -287,5 +302,5 @@
|
287 |
302 |
struct SetStandardElevator
|
288 |
|
: public Circulation<Digraph, LCapMap, UCapMap, DeltaMap,
|
|
303 |
: public Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
|
289 |
304 |
SetStandardElevatorTraits<_Elevator> > {
|
290 |
|
typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap,
|
|
305 |
typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
|
291 |
306 |
SetStandardElevatorTraits<_Elevator> > Create;
|
... |
... |
@@ -301,14 +316,16 @@
|
301 |
316 |
|
302 |
|
/// The constructor of the class.
|
|
317 |
/// Constructor.
|
303 |
318 |
|
304 |
319 |
/// The constructor of the class.
|
305 |
|
/// \param g The digraph the algorithm runs on.
|
306 |
|
/// \param lo The lower bound capacity of the arcs.
|
307 |
|
/// \param up The upper bound capacity of the arcs.
|
308 |
|
/// \param delta The lower bound for the supply of the nodes.
|
309 |
|
Circulation(const Digraph &g,const LCapMap &lo,
|
310 |
|
const UCapMap &up,const DeltaMap &delta)
|
311 |
|
: _g(g), _node_num(),
|
312 |
|
_lo(&lo),_up(&up),_delta(&delta),_flow(0),_local_flow(false),
|
313 |
|
_level(0), _local_level(false), _excess(0), _el() {}
|
|
320 |
///
|
|
321 |
/// \param graph The digraph the algorithm runs on.
|
|
322 |
/// \param lower The lower bounds for the flow values on the arcs.
|
|
323 |
/// \param upper The upper bounds (capacities) for the flow values
|
|
324 |
/// on the arcs.
|
|
325 |
/// \param supply The signed supply values of the nodes.
|
|
326 |
Circulation(const Digraph &graph, const LowerMap &lower,
|
|
327 |
const UpperMap &upper, const SupplyMap &supply)
|
|
328 |
: _g(graph), _lo(&lower), _up(&upper), _supply(&supply),
|
|
329 |
_flow(NULL), _local_flow(false), _level(NULL), _local_level(false),
|
|
330 |
_excess(NULL) {}
|
314 |
331 |
|
... |
... |
@@ -352,7 +369,7 @@
|
352 |
369 |
|
353 |
|
/// Sets the lower bound capacity map.
|
|
370 |
/// Sets the lower bound map.
|
354 |
371 |
|
355 |
|
/// Sets the lower bound capacity map.
|
|
372 |
/// Sets the lower bound map.
|
356 |
373 |
/// \return <tt>(*this)</tt>
|
357 |
|
Circulation& lowerCapMap(const LCapMap& map) {
|
|
374 |
Circulation& lowerMap(const LowerMap& map) {
|
358 |
375 |
_lo = ↦
|
... |
... |
@@ -361,7 +378,7 @@
|
361 |
378 |
|
362 |
|
/// Sets the upper bound capacity map.
|
|
379 |
/// Sets the upper bound (capacity) map.
|
363 |
380 |
|
364 |
|
/// Sets the upper bound capacity map.
|
|
381 |
/// Sets the upper bound (capacity) map.
|
365 |
382 |
/// \return <tt>(*this)</tt>
|
366 |
|
Circulation& upperCapMap(const LCapMap& map) {
|
|
383 |
Circulation& upperMap(const LowerMap& map) {
|
367 |
384 |
_up = ↦
|
... |
... |
@@ -370,8 +387,8 @@
|
370 |
387 |
|
371 |
|
/// Sets the lower bound map for the supply of the nodes.
|
|
388 |
/// Sets the supply map.
|
372 |
389 |
|
373 |
|
/// Sets the lower bound map for the supply of the nodes.
|
|
390 |
/// Sets the supply map.
|
374 |
391 |
/// \return <tt>(*this)</tt>
|
375 |
|
Circulation& deltaMap(const DeltaMap& map) {
|
376 |
|
_delta = ↦
|
|
392 |
Circulation& supplyMap(const SupplyMap& map) {
|
|
393 |
_supply = ↦
|
377 |
394 |
return *this;
|
... |
... |
@@ -455,3 +472,3 @@
|
455 |
472 |
for(NodeIt n(_g);n!=INVALID;++n) {
|
456 |
|
_excess->set(n, (*_delta)[n]);
|
|
473 |
_excess->set(n, (*_supply)[n]);
|
457 |
474 |
}
|
... |
... |
@@ -484,3 +501,3 @@
|
484 |
501 |
for(NodeIt n(_g);n!=INVALID;++n) {
|
485 |
|
_excess->set(n, (*_delta)[n]);
|
|
502 |
_excess->set(n, (*_supply)[n]);
|
486 |
503 |
}
|
... |
... |
@@ -497,3 +514,3 @@
|
497 |
514 |
} else {
|
498 |
|
Value fc = -(*_excess)[_g.target(e)];
|
|
515 |
Flow fc = -(*_excess)[_g.target(e)];
|
499 |
516 |
_flow->set(e, fc);
|
... |
... |
@@ -530,3 +547,3 @@
|
530 |
547 |
int mlevel=_node_num;
|
531 |
|
Value exc=(*_excess)[act];
|
|
548 |
Flow exc=(*_excess)[act];
|
532 |
549 |
|
... |
... |
@@ -534,3 +551,3 @@
|
534 |
551 |
Node v = _g.target(e);
|
535 |
|
Value fc=(*_up)[e]-(*_flow)[e];
|
|
552 |
Flow fc=(*_up)[e]-(*_flow)[e];
|
536 |
553 |
if(!_tol.positive(fc)) continue;
|
... |
... |
@@ -558,3 +575,3 @@
|
558 |
575 |
Node v = _g.source(e);
|
559 |
|
Value fc=(*_flow)[e]-(*_lo)[e];
|
|
576 |
Flow fc=(*_flow)[e]-(*_lo)[e];
|
560 |
577 |
if(!_tol.positive(fc)) continue;
|
... |
... |
@@ -634,3 +651,3 @@
|
634 |
651 |
/// using this function.
|
635 |
|
Value flow(const Arc& arc) const {
|
|
652 |
Flow flow(const Arc& arc) const {
|
636 |
653 |
return (*_flow)[arc];
|
... |
... |
@@ -653,4 +670,4 @@
|
653 |
670 |
|
654 |
|
\f[ \sum_{a\in\delta_{out}(B)} upper(a) -
|
655 |
|
\sum_{a\in\delta_{in}(B)} lower(a) < \sum_{v\in B}delta(v) \f]
|
|
671 |
\f[ \sum_{uv\in A: u\in B} upper(uv) -
|
|
672 |
\sum_{uv\in A: v\in B} lower(uv) < \sum_{v\in B} sup(v) \f]
|
656 |
673 |
|
... |
... |
@@ -717,3 +734,3 @@
|
717 |
734 |
{
|
718 |
|
Value dif=-(*_delta)[n];
|
|
735 |
Flow dif=-(*_supply)[n];
|
719 |
736 |
for(InArcIt e(_g,n);e!=INVALID;++e) dif-=(*_flow)[e];
|
... |
... |
@@ -732,6 +749,6 @@
|
732 |
749 |
{
|
733 |
|
Value delta=0;
|
|
750 |
Flow delta=0;
|
734 |
751 |
for(NodeIt n(_g);n!=INVALID;++n)
|
735 |
752 |
if(barrier(n))
|
736 |
|
delta-=(*_delta)[n];
|
|
753 |
delta-=(*_supply)[n];
|
737 |
754 |
for(ArcIt e(_g);e!=INVALID;++e)
|