[Lemon-commits] [lemon_svn] jacint: r806 - hugo/trunk/src/work/jacint
Lemon SVN
svn at lemon.cs.elte.hu
Mon Nov 6 20:41:35 CET 2006
Author: jacint
Date: Wed May 12 12:51:53 2004
New Revision: 806
Added:
hugo/trunk/src/work/jacint/max_save.h
Log:
Added: hugo/trunk/src/work/jacint/max_save.h
==============================================================================
--- (empty file)
+++ hugo/trunk/src/work/jacint/max_save.h Wed May 12 12:51:53 2004
@@ -0,0 +1,1136 @@
+// -*- C++ -*-
+#ifndef HUGO_MAX_FLOW_H
+#define HUGO_MAX_FLOW_H
+
+///\ingroup galgs
+///\file
+///\brief Maximum flow algorithm.
+
+#define H0 20
+#define H1 1
+
+#include <vector>
+#include <queue>
+#include <stack>
+
+#include <graph_wrapper.h>
+#include <bfs_iterator.h>
+#include <invalid.h>
+#include <maps.h>
+#include <for_each_macros.h>
+
+/// \file
+/// \brief Dimacs file format reader.
+
+namespace hugo {
+
+ /// \addtogroup galgs
+ /// @{
+
+ ///Maximum flow algorithms class.
+
+ ///This class provides various algorithms for finding a flow of
+ ///maximum value in a directed graph. The \e source node, the \e
+ ///target node, the \e capacity of the edges and the \e starting \e
+ ///flow value of the edges can be passed to the algorithm by the
+ ///constructor. It is possible to change these quantities using the
+ ///functions \ref resetSource, \ref resetTarget, \ref resetCap and
+ ///\ref resetFlow. Before any subsequent runs of any algorithm of
+ ///the class \ref resetFlow should be called, otherwise it will
+ ///start from a maximum flow.
+
+ ///After running an algorithm of the class, the maximum value of a
+ ///value can be obtained by calling \ref flowValue(). The minimum
+ ///value cut can be written into a \c node map of \c bools by
+ ///calling \ref minCut. (\ref minMinCut and \ref maxMinCut writes
+ ///the inclusionwise minimum and maximum of the minimum value
+ ///cuts, resp.)
+
+ ///\param Graph The undirected graph type the algorithm runs on.
+ ///\param Num The number type of the capacities and the flow values.
+ ///\param The type of the capacity map.
+ ///\param The type of the flow map.
+
+ ///\author Marton Makai, Jacint Szabo
+ template <typename Graph, typename Num,
+ typename CapMap=typename Graph::template EdgeMap<Num>,
+ typename FlowMap=typename Graph::template EdgeMap<Num> >
+ class MaxFlow {
+
+ typedef typename Graph::Node Node;
+ typedef typename Graph::NodeIt NodeIt;
+ typedef typename Graph::OutEdgeIt OutEdgeIt;
+ typedef typename Graph::InEdgeIt InEdgeIt;
+
+ typedef typename std::vector<std::stack<Node> > VecStack;
+ typedef typename Graph::template NodeMap<Node> NNMap;
+ typedef typename std::vector<Node> VecNode;
+
+ typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
+ typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
+ typedef typename ResGW::Edge ResGWEdge;
+ //typedef typename ResGW::template NodeMap<bool> ReachedMap; //fixme
+ typedef typename Graph::template NodeMap<int> ReachedMap;
+
+ const Graph* g;
+ Node s;
+ Node t;
+ const CapMap* capacity;
+ FlowMap* flow;
+ int n; //the number of nodes of G
+
+ //level works as a bool map in augmenting path algorithms and is
+ //used by bfs for storing reached information. In preflow, it
+ //shows the levels of nodes.
+ ReachedMap level;
+
+ //excess is needed only in preflow
+ typename Graph::template NodeMap<Num> excess;
+
+
+ //fixme
+ // protected:
+ // MaxFlow() { }
+ // void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
+ // FlowMap& _flow)
+ // {
+ // g=&_G;
+ // s=_s;
+ // t=_t;
+ // capacity=&_capacity;
+ // flow=&_flow;
+ // n=_G.nodeNum;
+ // level.set (_G); //kellene vmi ilyesmi fv
+ // excess(_G,0); //itt is
+ // }
+
+ public:
+
+ ///Indicates the property of the starting flow.
+
+ ///Indicates the property of the starting flow. The meanings:
+ ///- \c ZERO_FLOW: constant zero flow
+ ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
+ ///the sum of the out-flows in every node except the source and
+ ///the target.
+ ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at
+ ///least the sum of the out-flows in every node except the source.
+ enum flowEnum{
+ ZERO_FLOW=0,
+ GEN_FLOW=1,
+ PRE_FLOW=2
+ };
+
+ MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
+ FlowMap& _flow) :
+ g(&_G), s(_s), t(_t), capacity(&_capacity),
+ flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0) {}
+
+ ///Runs a maximum flow algorithm.
+
+ ///Runs a preflow algorithm, which is the fastest maximum flow
+ ///algorithm up-to-date. The default for \c fe is ZERO_FLOW.
+ ///\pre The starting flow must be a
+ /// - constant zero flow if \c fe is \c ZERO_FLOW,
+ /// - an arbitary flow if \c fe is \c GEN_FLOW,
+ /// - an arbitary preflow if \c fe is \c PRE_FLOW.
+ void run( flowEnum fe=ZERO_FLOW ) {
+ preflow(fe);
+ }
+
+ ///Runs a preflow algorithm.
+
+ ///Runs a preflow algorithm. The preflow algorithms provide the
+ ///fastest way to compute a maximum flow in a directed graph.
+ ///\pre The starting flow must be a
+ /// - constant zero flow if \c fe is \c ZERO_FLOW,
+ /// - an arbitary flow if \c fe is \c GEN_FLOW,
+ /// - an arbitary preflow if \c fe is \c PRE_FLOW.
+ void preflow(flowEnum fe) {
+ preflowPhase1(fe);
+ preflowPhase2();
+ }
+ // Heuristics:
+ // 2 phase
+ // gap
+ // list 'level_list' on the nodes on level i implemented by hand
+ // stack 'active' on the active nodes on level i
+ // runs heuristic 'highest label' for H1*n relabels
+ // runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
+ // Parameters H0 and H1 are initialized to 20 and 1.
+
+ ///Runs the first phase of the preflow algorithm.
+
+ ///The preflow algorithm consists of two phases, this method runs the
+ ///first phase. After the first phase the maximum flow value and a
+ ///minimum value cut can already be computed, though a maximum flow
+ ///is net yet obtained. So after calling this method \ref flowValue
+ ///and \ref actMinCut gives proper results.
+ ///\warning: \ref minCut, \ref minMinCut and \ref maxMinCut do not
+ ///give minimum value cuts unless calling \ref preflowPhase2.
+ ///\pre The starting flow must be a
+ /// - constant zero flow if \c fe is \c ZERO_FLOW,
+ /// - an arbitary flow if \c fe is \c GEN_FLOW,
+ /// - an arbitary preflow if \c fe is \c PRE_FLOW.
+ void preflowPhase1( flowEnum fe );
+
+ ///Runs the second phase of the preflow algorithm.
+
+ ///The preflow algorithm consists of two phases, this method runs
+ ///the second phase. After calling \ref preflowPhase1 and then
+ ///\ref preflowPhase2 the methods \ref flowValue, \ref minCut,
+ ///\ref minMinCut and \ref maxMinCut give proper results.
+ ///\pre \ref preflowPhase1 must be called before.
+ void preflowPhase2();
+
+ /// Starting from a flow, this method searches for an augmenting path
+ /// according to the Edmonds-Karp algorithm
+ /// and augments the flow on if any.
+ /// The return value shows if the augmentation was successful.
+ bool augmentOnShortestPath();
+
+ /// Starting from a flow, this method searches for an augmenting blockin
+ /// flow according to Dinits' algorithm and augments the flow on if any.
+ /// The blocking flow is computed in a physically constructed
+ /// residual graph of type \c Mutablegraph.
+ /// The return value show sif the augmentation was succesful.
+ template<typename MutableGraph> bool augmentOnBlockingFlow();
+
+ /// The same as \c augmentOnBlockingFlow<MutableGraph> but the
+ /// residual graph is not constructed physically.
+ /// The return value shows if the augmentation was succesful.
+ bool augmentOnBlockingFlow2();
+
+ /// Returns the actual flow value.
+ /// More precisely, it returns the negative excess of s, thus
+ /// this works also for preflows.
+ ///Can be called already after \ref preflowPhase1.
+
+ Num flowValue() {
+ Num a=0;
+ FOR_EACH_INC_LOC(OutEdgeIt, e, *g, s) a+=(*flow)[e];
+ FOR_EACH_INC_LOC(InEdgeIt, e, *g, s) a-=(*flow)[e];
+ return a;
+ //marci figyu: excess[t] epp ezt adja preflow 0. fazisa utan
+ }
+
+ ///Returns a minimum value cut after calling \ref preflowPhase1.
+
+ ///After the first phase of the preflow algorithm the maximum flow
+ ///value and a minimum value cut can already be computed. This
+ ///method can be called after running \ref preflowPhase1 for
+ ///obtaining a minimum value cut.
+ ///\warning: Gives proper result only right after calling \ref
+ ///preflowPhase1.
+ ///\todo We have to make some status variable which shows the actual state
+ /// of the class. This enables us to determine which methods are valid
+ /// for MinCut computation
+ template<typename _CutMap>
+ void actMinCut(_CutMap& M) {
+ NodeIt v;
+ for(g->first(v); g->valid(v); g->next(v)) {
+ if ( level[v] < n ) {
+ M.set(v,false);
+ } else {
+ M.set(v,true);
+ }
+ }
+ }
+
+ ///Returns the inclusionwise minimum of the minimum value cuts.
+
+ ///Sets \c M to the characteristic vector of the minimum value cut
+ ///which is inclusionwise minimum. It is computed by processing
+ ///a bfs from the source node \c s in the residual graph.
+ ///\pre M should be a node map of bools initialized to false.
+ ///\pre \c flow must be a maximum flow.
+ template<typename _CutMap>
+ void minMinCut(_CutMap& M) {
+
+ std::queue<Node> queue;
+
+ M.set(s,true);
+ queue.push(s);
+
+ while (!queue.empty()) {
+ Node w=queue.front();
+ queue.pop();
+
+ OutEdgeIt e;
+ for(g->first(e,w) ; g->valid(e); g->next(e)) {
+ Node v=g->head(e);
+ if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
+ queue.push(v);
+ M.set(v, true);
+ }
+ }
+
+ InEdgeIt f;
+ for(g->first(f,w) ; g->valid(f); g->next(f)) {
+ Node v=g->tail(f);
+ if (!M[v] && (*flow)[f] > 0 ) {
+ queue.push(v);
+ M.set(v, true);
+ }
+ }
+ }
+ }
+
+
+ ///Returns the inclusionwise maximum of the minimum value cuts.
+
+ ///Sets \c M to the characteristic vector of the minimum value cut
+ ///which is inclusionwise maximum. It is computed by processing a
+ ///backward bfs from the target node \c t in the residual graph.
+ ///\pre M should be a node map of bools initialized to false.
+ ///\pre \c flow must be a maximum flow.
+ template<typename _CutMap>
+ void maxMinCut(_CutMap& M) {
+
+ NodeIt v;
+ for(g->first(v) ; g->valid(v); g->next(v)) {
+ M.set(v, true);
+ }
+
+ std::queue<Node> queue;
+
+ M.set(t,false);
+ queue.push(t);
+
+ while (!queue.empty()) {
+ Node w=queue.front();
+ queue.pop();
+
+
+ InEdgeIt e;
+ for(g->first(e,w) ; g->valid(e); g->next(e)) {
+ Node v=g->tail(e);
+ if (M[v] && (*flow)[e] < (*capacity)[e] ) {
+ queue.push(v);
+ M.set(v, false);
+ }
+ }
+
+ OutEdgeIt f;
+ for(g->first(f,w) ; g->valid(f); g->next(f)) {
+ Node v=g->head(f);
+ if (M[v] && (*flow)[f] > 0 ) {
+ queue.push(v);
+ M.set(v, false);
+ }
+ }
+ }
+ }
+
+
+ ///Returns a minimum value cut.
+
+ ///Sets \c M to the characteristic vector of a minimum value cut.
+ ///\pre M should be a node map of bools initialized to false.
+ ///\pre \c flow must be a maximum flow.
+ template<typename CutMap>
+ void minCut(CutMap& M) { minMinCut(M); }
+
+ ///Resets the source node to \c _s.
+
+ ///Resets the source node to \c _s.
+ ///
+ void resetSource(Node _s) { s=_s; }
+
+
+ ///Resets the target node to \c _t.
+
+ ///Resets the target node to \c _t.
+ ///
+ void resetTarget(Node _t) { t=_t; }
+
+ /// Resets the edge map of the capacities to _cap.
+
+ /// Resets the edge map of the capacities to _cap.
+ ///
+ void resetCap(const CapMap& _cap) { capacity=&_cap; }
+
+ /// Resets the edge map of the flows to _flow.
+
+ /// Resets the edge map of the flows to _flow.
+ ///
+ void resetFlow(FlowMap& _flow) { flow=&_flow; }
+
+
+ private:
+
+ int push(Node w, VecStack& active) {
+
+ int lev=level[w];
+ Num exc=excess[w];
+ int newlevel=n; //bound on the next level of w
+
+ OutEdgeIt e;
+ for(g->first(e,w); g->valid(e); g->next(e)) {
+
+ if ( (*flow)[e] >= (*capacity)[e] ) continue;
+ Node v=g->head(e);
+
+ if( lev > level[v] ) { //Push is allowed now
+
+ if ( excess[v]<=0 && v!=t && v!=s ) {
+ int lev_v=level[v];
+ active[lev_v].push(v);
+ }
+
+ Num cap=(*capacity)[e];
+ Num flo=(*flow)[e];
+ Num remcap=cap-flo;
+
+ if ( remcap >= exc ) { //A nonsaturating push.
+
+ flow->set(e, flo+exc);
+ excess.set(v, excess[v]+exc);
+ exc=0;
+ break;
+
+ } else { //A saturating push.
+ flow->set(e, cap);
+ excess.set(v, excess[v]+remcap);
+ exc-=remcap;
+ }
+ } else if ( newlevel > level[v] ) newlevel = level[v];
+ } //for out edges wv
+
+ if ( exc > 0 ) {
+ InEdgeIt e;
+ for(g->first(e,w); g->valid(e); g->next(e)) {
+
+ if( (*flow)[e] <= 0 ) continue;
+ Node v=g->tail(e);
+
+ if( lev > level[v] ) { //Push is allowed now
+
+ if ( excess[v]<=0 && v!=t && v!=s ) {
+ int lev_v=level[v];
+ active[lev_v].push(v);
+ }
+
+ Num flo=(*flow)[e];
+
+ if ( flo >= exc ) { //A nonsaturating push.
+
+ flow->set(e, flo-exc);
+ excess.set(v, excess[v]+exc);
+ exc=0;
+ break;
+ } else { //A saturating push.
+
+ excess.set(v, excess[v]+flo);
+ exc-=flo;
+ flow->set(e,0);
+ }
+ } else if ( newlevel > level[v] ) newlevel = level[v];
+ } //for in edges vw
+
+ } // if w still has excess after the out edge for cycle
+
+ excess.set(w, exc);
+
+ return newlevel;
+ }
+
+
+ void preflowPreproc ( flowEnum fe, VecStack& active,
+ VecNode& level_list, NNMap& left, NNMap& right ) {
+
+ std::queue<Node> bfs_queue;
+
+ switch ( fe ) {
+ case ZERO_FLOW:
+ {
+ //Reverse_bfs from t, to find the starting level.
+ level.set(t,0);
+ bfs_queue.push(t);
+
+ while (!bfs_queue.empty()) {
+
+ Node v=bfs_queue.front();
+ bfs_queue.pop();
+ int l=level[v]+1;
+
+ InEdgeIt e;
+ for(g->first(e,v); g->valid(e); g->next(e)) {
+ Node w=g->tail(e);
+ if ( level[w] == n && w != s ) {
+ bfs_queue.push(w);
+ Node first=level_list[l];
+ if ( g->valid(first) ) left.set(first,w);
+ right.set(w,first);
+ level_list[l]=w;
+ level.set(w, l);
+ }
+ }
+ }
+
+ //the starting flow
+ OutEdgeIt e;
+ for(g->first(e,s); g->valid(e); g->next(e))
+ {
+ Num c=(*capacity)[e];
+ if ( c <= 0 ) continue;
+ Node w=g->head(e);
+ if ( level[w] < n ) {
+ if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
+ flow->set(e, c);
+ excess.set(w, excess[w]+c);
+ }
+ }
+ break;
+ }
+
+ case GEN_FLOW:
+ case PRE_FLOW:
+ {
+ //Reverse_bfs from t in the residual graph,
+ //to find the starting level.
+ level.set(t,0);
+ bfs_queue.push(t);
+
+ while (!bfs_queue.empty()) {
+
+ Node v=bfs_queue.front();
+ bfs_queue.pop();
+ int l=level[v]+1;
+
+ InEdgeIt e;
+ for(g->first(e,v); g->valid(e); g->next(e)) {
+ if ( (*capacity)[e] <= (*flow)[e] ) continue;
+ Node w=g->tail(e);
+ if ( level[w] == n && w != s ) {
+ bfs_queue.push(w);
+ Node first=level_list[l];
+ if ( g->valid(first) ) left.set(first,w);
+ right.set(w,first);
+ level_list[l]=w;
+ level.set(w, l);
+ }
+ }
+
+ OutEdgeIt f;
+ for(g->first(f,v); g->valid(f); g->next(f)) {
+ if ( 0 >= (*flow)[f] ) continue;
+ Node w=g->head(f);
+ if ( level[w] == n && w != s ) {
+ bfs_queue.push(w);
+ Node first=level_list[l];
+ if ( g->valid(first) ) left.set(first,w);
+ right.set(w,first);
+ level_list[l]=w;
+ level.set(w, l);
+ }
+ }
+ }
+
+
+ //the starting flow
+ OutEdgeIt e;
+ for(g->first(e,s); g->valid(e); g->next(e))
+ {
+ Num rem=(*capacity)[e]-(*flow)[e];
+ if ( rem <= 0 ) continue;
+ Node w=g->head(e);
+ if ( level[w] < n ) {
+ if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
+ flow->set(e, (*capacity)[e]);
+ excess.set(w, excess[w]+rem);
+ }
+ }
+
+ InEdgeIt f;
+ for(g->first(f,s); g->valid(f); g->next(f))
+ {
+ if ( (*flow)[f] <= 0 ) continue;
+ Node w=g->tail(f);
+ if ( level[w] < n ) {
+ if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
+ excess.set(w, excess[w]+(*flow)[f]);
+ flow->set(f, 0);
+ }
+ }
+ break;
+ } //case PRE_FLOW
+ }
+ } //preflowPreproc
+
+
+
+ void relabel(Node w, int newlevel, VecStack& active,
+ VecNode& level_list, NNMap& left,
+ NNMap& right, int& b, int& k, bool what_heur )
+ {
+
+ Num lev=level[w];
+
+ Node right_n=right[w];
+ Node left_n=left[w];
+
+ //unlacing starts
+ if ( g->valid(right_n) ) {
+ if ( g->valid(left_n) ) {
+ right.set(left_n, right_n);
+ left.set(right_n, left_n);
+ } else {
+ level_list[lev]=right_n;
+ left.set(right_n, INVALID);
+ }
+ } else {
+ if ( g->valid(left_n) ) {
+ right.set(left_n, INVALID);
+ } else {
+ level_list[lev]=INVALID;
+ }
+ }
+ //unlacing ends
+
+ if ( !g->valid(level_list[lev]) ) {
+
+ //gapping starts
+ for (int i=lev; i!=k ; ) {
+ Node v=level_list[++i];
+ while ( g->valid(v) ) {
+ level.set(v,n);
+ v=right[v];
+ }
+ level_list[i]=INVALID;
+ if ( !what_heur ) {
+ while ( !active[i].empty() ) {
+ active[i].pop(); //FIXME: ezt szebben kene
+ }
+ }
+ }
+
+ level.set(w,n);
+ b=lev-1;
+ k=b;
+ //gapping ends
+
+ } else {
+
+ if ( newlevel == n ) level.set(w,n);
+ else {
+ level.set(w,++newlevel);
+ active[newlevel].push(w);
+ if ( what_heur ) b=newlevel;
+ if ( k < newlevel ) ++k; //now k=newlevel
+ Node first=level_list[newlevel];
+ if ( g->valid(first) ) left.set(first,w);
+ right.set(w,first);
+ left.set(w,INVALID);
+ level_list[newlevel]=w;
+ }
+ }
+
+ } //relabel
+
+
+ template<typename MapGraphWrapper>
+ class DistanceMap {
+ protected:
+ const MapGraphWrapper* g;
+ typename MapGraphWrapper::template NodeMap<int> dist;
+ public:
+ DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
+ void set(const typename MapGraphWrapper::Node& n, int a) {
+ dist.set(n, a);
+ }
+ int operator[](const typename MapGraphWrapper::Node& n)
+ { return dist[n]; }
+ // int get(const typename MapGraphWrapper::Node& n) const {
+ // return dist[n]; }
+ // bool get(const typename MapGraphWrapper::Edge& e) const {
+ // return (dist.get(g->tail(e))<dist.get(g->head(e))); }
+ bool operator[](const typename MapGraphWrapper::Edge& e) const {
+ return (dist[g->tail(e)]<dist[g->head(e)]);
+ }
+ };
+
+ };
+
+
+ template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+ void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1( flowEnum fe )
+ {
+
+ int heur0=(int)(H0*n); //time while running 'bound decrease'
+ int heur1=(int)(H1*n); //time while running 'highest label'
+ int heur=heur1; //starting time interval (#of relabels)
+ int numrelabel=0;
+
+ bool what_heur=1;
+ //It is 0 in case 'bound decrease' and 1 in case 'highest label'
+
+ bool end=false;
+ //Needed for 'bound decrease', true means no active nodes are above bound b.
+
+ int k=n-2; //bound on the highest level under n containing a node
+ int b=k; //bound on the highest level under n of an active node
+
+ VecStack active(n);
+
+ NNMap left(*g, INVALID);
+ NNMap right(*g, INVALID);
+ VecNode level_list(n,INVALID);
+ //List of the nodes in level i<n, set to n.
+
+ NodeIt v;
+ for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
+ //setting each node to level n
+
+ switch ( fe ) {
+ case PRE_FLOW:
+ {
+ //counting the excess
+ NodeIt v;
+ for(g->first(v); g->valid(v); g->next(v)) {
+ Num exc=0;
+
+ InEdgeIt e;
+ for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
+ OutEdgeIt f;
+ for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
+
+ excess.set(v,exc);
+
+ //putting the active nodes into the stack
+ int lev=level[v];
+ if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
+ }
+ break;
+ }
+ case GEN_FLOW:
+ {
+ //Counting the excess of t
+ Num exc=0;
+
+ InEdgeIt e;
+ for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
+ OutEdgeIt f;
+ for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
+
+ excess.set(t,exc);
+
+ break;
+ }
+ default:
+ break;
+ }
+
+ preflowPreproc( fe, active, level_list, left, right );
+ //End of preprocessing
+
+
+ //Push/relabel on the highest level active nodes.
+ while ( true ) {
+ if ( b == 0 ) {
+ if ( !what_heur && !end && k > 0 ) {
+ b=k;
+ end=true;
+ } else break;
+ }
+
+ if ( active[b].empty() ) --b;
+ else {
+ end=false;
+ Node w=active[b].top();
+ active[b].pop();
+ int newlevel=push(w,active);
+ if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list,
+ left, right, b, k, what_heur);
+
+ ++numrelabel;
+ if ( numrelabel >= heur ) {
+ numrelabel=0;
+ if ( what_heur ) {
+ what_heur=0;
+ heur=heur0;
+ end=false;
+ } else {
+ what_heur=1;
+ heur=heur1;
+ b=k;
+ }
+ }
+ }
+ }
+ }
+
+
+
+ template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+ void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase2()
+ {
+
+ int k=n-2; //bound on the highest level under n containing a node
+ int b=k; //bound on the highest level under n of an active node
+
+ VecStack active(n);
+ level.set(s,0);
+ std::queue<Node> bfs_queue;
+ bfs_queue.push(s);
+
+ while (!bfs_queue.empty()) {
+
+ Node v=bfs_queue.front();
+ bfs_queue.pop();
+ int l=level[v]+1;
+
+ InEdgeIt e;
+ for(g->first(e,v); g->valid(e); g->next(e)) {
+ if ( (*capacity)[e] <= (*flow)[e] ) continue;
+ Node u=g->tail(e);
+ if ( level[u] >= n ) {
+ bfs_queue.push(u);
+ level.set(u, l);
+ if ( excess[u] > 0 ) active[l].push(u);
+ }
+ }
+
+ OutEdgeIt f;
+ for(g->first(f,v); g->valid(f); g->next(f)) {
+ if ( 0 >= (*flow)[f] ) continue;
+ Node u=g->head(f);
+ if ( level[u] >= n ) {
+ bfs_queue.push(u);
+ level.set(u, l);
+ if ( excess[u] > 0 ) active[l].push(u);
+ }
+ }
+ }
+ b=n-2;
+
+ while ( true ) {
+
+ if ( b == 0 ) break;
+
+ if ( active[b].empty() ) --b;
+ else {
+ Node w=active[b].top();
+ active[b].pop();
+ int newlevel=push(w,active);
+
+ //relabel
+ if ( excess[w] > 0 ) {
+ level.set(w,++newlevel);
+ active[newlevel].push(w);
+ b=newlevel;
+ }
+ } // if stack[b] is nonempty
+ } // while(true)
+ }
+
+
+
+ template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+ bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath()
+ {
+ ResGW res_graph(*g, *capacity, *flow);
+ bool _augment=false;
+
+ //ReachedMap level(res_graph);
+ FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
+ BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
+ bfs.pushAndSetReached(s);
+
+ typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
+ pred.set(s, INVALID);
+
+ typename ResGW::template NodeMap<Num> free(res_graph);
+
+ //searching for augmenting path
+ while ( !bfs.finished() ) {
+ ResGWOutEdgeIt e=bfs;
+ if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
+ Node v=res_graph.tail(e);
+ Node w=res_graph.head(e);
+ pred.set(w, e);
+ if (res_graph.valid(pred[v])) {
+ free.set(w, std::min(free[v], res_graph.resCap(e)));
+ } else {
+ free.set(w, res_graph.resCap(e));
+ }
+ if (res_graph.head(e)==t) { _augment=true; break; }
+ }
+
+ ++bfs;
+ } //end of searching augmenting path
+
+ if (_augment) {
+ Node n=t;
+ Num augment_value=free[t];
+ while (res_graph.valid(pred[n])) {
+ ResGWEdge e=pred[n];
+ res_graph.augment(e, augment_value);
+ n=res_graph.tail(e);
+ }
+ }
+
+ return _augment;
+ }
+
+
+
+
+
+
+
+
+
+ template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+ template<typename MutableGraph>
+ bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow()
+ {
+ typedef MutableGraph MG;
+ bool _augment=false;
+
+ ResGW res_graph(*g, *capacity, *flow);
+
+ //bfs for distances on the residual graph
+ //ReachedMap level(res_graph);
+ FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
+ BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
+ bfs.pushAndSetReached(s);
+ typename ResGW::template NodeMap<int>
+ dist(res_graph); //filled up with 0's
+
+ //F will contain the physical copy of the residual graph
+ //with the set of edges which are on shortest paths
+ MG F;
+ typename ResGW::template NodeMap<typename MG::Node>
+ res_graph_to_F(res_graph);
+ {
+ typename ResGW::NodeIt n;
+ for(res_graph.first(n); res_graph.valid(n); res_graph.next(n)) {
+ res_graph_to_F.set(n, F.addNode());
+ }
+ }
+
+ typename MG::Node sF=res_graph_to_F[s];
+ typename MG::Node tF=res_graph_to_F[t];
+ typename MG::template EdgeMap<ResGWEdge> original_edge(F);
+ typename MG::template EdgeMap<Num> residual_capacity(F);
+
+ while ( !bfs.finished() ) {
+ ResGWOutEdgeIt e=bfs;
+ if (res_graph.valid(e)) {
+ if (bfs.isBNodeNewlyReached()) {
+ dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
+ typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]);
+ original_edge.update();
+ original_edge.set(f, e);
+ residual_capacity.update();
+ residual_capacity.set(f, res_graph.resCap(e));
+ } else {
+ if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) {
+ typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]);
+ original_edge.update();
+ original_edge.set(f, e);
+ residual_capacity.update();
+ residual_capacity.set(f, res_graph.resCap(e));
+ }
+ }
+ }
+ ++bfs;
+ } //computing distances from s in the residual graph
+
+ bool __augment=true;
+
+ while (__augment) {
+ __augment=false;
+ //computing blocking flow with dfs
+ DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
+ typename MG::template NodeMap<typename MG::Edge> pred(F);
+ pred.set(sF, INVALID);
+ //invalid iterators for sources
+
+ typename MG::template NodeMap<Num> free(F);
+
+ dfs.pushAndSetReached(sF);
+ while (!dfs.finished()) {
+ ++dfs;
+ if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
+ if (dfs.isBNodeNewlyReached()) {
+ typename MG::Node v=F.aNode(dfs);
+ typename MG::Node w=F.bNode(dfs);
+ pred.set(w, dfs);
+ if (F.valid(pred[v])) {
+ free.set(w, std::min(free[v], residual_capacity[dfs]));
+ } else {
+ free.set(w, residual_capacity[dfs]);
+ }
+ if (w==tF) {
+ __augment=true;
+ _augment=true;
+ break;
+ }
+
+ } else {
+ F.erase(/*typename MG::OutEdgeIt*/(dfs));
+ }
+ }
+ }
+
+ if (__augment) {
+ typename MG::Node n=tF;
+ Num augment_value=free[tF];
+ while (F.valid(pred[n])) {
+ typename MG::Edge e=pred[n];
+ res_graph.augment(original_edge[e], augment_value);
+ n=F.tail(e);
+ if (residual_capacity[e]==augment_value)
+ F.erase(e);
+ else
+ residual_capacity.set(e, residual_capacity[e]-augment_value);
+ }
+ }
+
+ }
+
+ return _augment;
+ }
+
+
+
+
+
+
+ template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+ bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2()
+ {
+ bool _augment=false;
+
+ ResGW res_graph(*g, *capacity, *flow);
+
+ //ReachedMap level(res_graph);
+ FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
+ BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
+
+ bfs.pushAndSetReached(s);
+ DistanceMap<ResGW> dist(res_graph);
+ while ( !bfs.finished() ) {
+ ResGWOutEdgeIt e=bfs;
+ if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
+ dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
+ }
+ ++bfs;
+ } //computing distances from s in the residual graph
+
+ //Subgraph containing the edges on some shortest paths
+ ConstMap<typename ResGW::Node, bool> true_map(true);
+ typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>,
+ DistanceMap<ResGW> > FilterResGW;
+ FilterResGW filter_res_graph(res_graph, true_map, dist);
+
+ //Subgraph, which is able to delete edges which are already
+ //met by the dfs
+ typename FilterResGW::template NodeMap<typename FilterResGW::OutEdgeIt>
+ first_out_edges(filter_res_graph);
+ typename FilterResGW::NodeIt v;
+ for(filter_res_graph.first(v); filter_res_graph.valid(v);
+ filter_res_graph.next(v))
+ {
+ typename FilterResGW::OutEdgeIt e;
+ filter_res_graph.first(e, v);
+ first_out_edges.set(v, e);
+ }
+ typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
+ template NodeMap<typename FilterResGW::OutEdgeIt> > ErasingResGW;
+ ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
+
+ bool __augment=true;
+
+ while (__augment) {
+
+ __augment=false;
+ //computing blocking flow with dfs
+ DfsIterator< ErasingResGW,
+ typename ErasingResGW::template NodeMap<bool> >
+ dfs(erasing_res_graph);
+ typename ErasingResGW::
+ template NodeMap<typename ErasingResGW::OutEdgeIt>
+ pred(erasing_res_graph);
+ pred.set(s, INVALID);
+ //invalid iterators for sources
+
+ typename ErasingResGW::template NodeMap<Num>
+ free1(erasing_res_graph);
+
+ dfs.pushAndSetReached(
+ typename ErasingResGW::Node(
+ typename FilterResGW::Node(
+ typename ResGW::Node(s)
+ )
+ )
+ );
+ while (!dfs.finished()) {
+ ++dfs;
+ if (erasing_res_graph.valid(
+ typename ErasingResGW::OutEdgeIt(dfs)))
+ {
+ if (dfs.isBNodeNewlyReached()) {
+
+ typename ErasingResGW::Node v=erasing_res_graph.aNode(dfs);
+ typename ErasingResGW::Node w=erasing_res_graph.bNode(dfs);
+
+ pred.set(w, /*typename ErasingResGW::OutEdgeIt*/(dfs));
+ if (erasing_res_graph.valid(pred[v])) {
+ free1.set(w, std::min(free1[v], res_graph.resCap(
+ typename ErasingResGW::OutEdgeIt(dfs))));
+ } else {
+ free1.set(w, res_graph.resCap(
+ typename ErasingResGW::OutEdgeIt(dfs)));
+ }
+
+ if (w==t) {
+ __augment=true;
+ _augment=true;
+ break;
+ }
+ } else {
+ erasing_res_graph.erase(dfs);
+ }
+ }
+ }
+
+ if (__augment) {
+ typename ErasingResGW::Node n=typename FilterResGW::Node(typename ResGW::Node(t));
+ // typename ResGW::NodeMap<Num> a(res_graph);
+ // typename ResGW::Node b;
+ // Num j=a[b];
+ // typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
+ // typename FilterResGW::Node b1;
+ // Num j1=a1[b1];
+ // typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
+ // typename ErasingResGW::Node b2;
+ // Num j2=a2[b2];
+ Num augment_value=free1[n];
+ while (erasing_res_graph.valid(pred[n])) {
+ typename ErasingResGW::OutEdgeIt e=pred[n];
+ res_graph.augment(e, augment_value);
+ n=erasing_res_graph.tail(e);
+ if (res_graph.resCap(e)==0)
+ erasing_res_graph.erase(e);
+ }
+ }
+
+ } //while (__augment)
+
+ return _augment;
+ }
+
+
+
+ /// @}
+
+} //END OF NAMESPACE HUGO
+
+#endif //HUGO_MAX_FLOW_H
+
+
+
+
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