marci@762: // -*- C++ -*-
marci@762: #ifndef HUGO_AUGMENTING_FLOW_H
marci@762: #define HUGO_AUGMENTING_FLOW_H
marci@762:
marci@762: #include <vector>
marci@762: #include <queue>
marci@762: #include <stack>
marci@762: #include <iostream>
marci@762:
marci@762: #include <hugo/graph_wrapper.h>
marci@762: #include <bfs_dfs.h>
marci@762: #include <hugo/invalid.h>
marci@762: #include <hugo/maps.h>
marci@777: //#include <for_each_macros.h>
marci@762:
marci@762: /// \file
marci@762: /// \brief Maximum flow algorithms.
marci@762: /// \ingroup galgs
marci@762:
marci@762: namespace hugo {
marci@762:
marci@762: /// \addtogroup galgs
marci@762: /// @{
marci@762: ///Maximum flow algorithms class.
marci@762:
marci@762: ///This class provides various algorithms for finding a flow of
marci@762: ///maximum value in a directed graph. The \e source node, the \e
marci@762: ///target node, the \e capacity of the edges and the \e starting \e
marci@762: ///flow value of the edges should be passed to the algorithm through the
marci@762: ///constructor. It is possible to change these quantities using the
marci@762: ///functions \ref resetSource, \ref resetTarget, \ref resetCap and
marci@762: ///\ref resetFlow. Before any subsequent runs of any algorithm of
marci@762: ///the class \ref resetFlow should be called.
marci@762:
marci@762: ///After running an algorithm of the class, the actual flow value
marci@762: ///can be obtained by calling \ref flowValue(). The minimum
marci@762: ///value cut can be written into a \c node map of \c bools by
marci@762: ///calling \ref minCut. (\ref minMinCut and \ref maxMinCut writes
marci@762: ///the inclusionwise minimum and maximum of the minimum value
marci@762: ///cuts, resp.)
marci@762: ///\param Graph The directed graph type the algorithm runs on.
marci@762: ///\param Num The number type of the capacities and the flow values.
marci@762: ///\param CapMap The capacity map type.
marci@762: ///\param FlowMap The flow map type.
marci@762: ///\author Marton Makai, Jacint Szabo
marci@762: // template <typename Graph, typename Num,
marci@762: // typename CapMap=typename Graph::template EdgeMap<Num>,
marci@762: // typename FlowMap=typename Graph::template EdgeMap<Num> >
marci@762: // class MaxFlow {
marci@762: // protected:
marci@762: // typedef typename Graph::Node Node;
marci@762: // typedef typename Graph::NodeIt NodeIt;
marci@762: // typedef typename Graph::EdgeIt EdgeIt;
marci@762: // typedef typename Graph::OutEdgeIt OutEdgeIt;
marci@762: // typedef typename Graph::InEdgeIt InEdgeIt;
marci@762:
marci@762: // typedef typename std::vector<std::stack<Node> > VecStack;
marci@762: // typedef typename Graph::template NodeMap<Node> NNMap;
marci@762: // typedef typename std::vector<Node> VecNode;
marci@762:
marci@762: // const Graph* g;
marci@762: // Node s;
marci@762: // Node t;
marci@762: // const CapMap* capacity;
marci@762: // FlowMap* flow;
marci@762: // int n; //the number of nodes of G
marci@762: // typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
marci@762: // //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
marci@762: // typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
marci@762: // typedef typename ResGW::Edge ResGWEdge;
marci@762: // //typedef typename ResGW::template NodeMap<bool> ReachedMap;
marci@762: // typedef typename Graph::template NodeMap<int> ReachedMap;
marci@762:
marci@762:
marci@762: // //level works as a bool map in augmenting path algorithms and is
marci@762: // //used by bfs for storing reached information. In preflow, it
marci@762: // //shows the levels of nodes.
marci@762: // ReachedMap level;
marci@762:
marci@762: // //excess is needed only in preflow
marci@762: // typename Graph::template NodeMap<Num> excess;
marci@762:
marci@762: // //fixme
marci@762: // // protected:
marci@762: // // MaxFlow() { }
marci@762: // // void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
marci@762: // // FlowMap& _flow)
marci@762: // // {
marci@762: // // g=&_G;
marci@762: // // s=_s;
marci@762: // // t=_t;
marci@762: // // capacity=&_capacity;
marci@762: // // flow=&_flow;
marci@762: // // n=_G.nodeNum;
marci@762: // // level.set (_G); //kellene vmi ilyesmi fv
marci@762: // // excess(_G,0); //itt is
marci@762: // // }
marci@762:
marci@762: // // constants used for heuristics
marci@762: // static const int H0=20;
marci@762: // static const int H1=1;
marci@762:
marci@762: // public:
marci@762:
marci@762: // ///Indicates the property of the starting flow.
marci@762:
marci@762: // ///Indicates the property of the starting flow. The meanings are as follows:
marci@762: // ///- \c ZERO_FLOW: constant zero flow
marci@762: // ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
marci@762: // ///the sum of the out-flows in every node except the \e source and
marci@762: // ///the \e target.
marci@762: // ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at
marci@762: // ///least the sum of the out-flows in every node except the \e source.
marci@762: // ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be
marci@762: // ///set to the constant zero flow in the beginning of the algorithm in this case.
marci@762: // enum FlowEnum{
marci@762: // ZERO_FLOW,
marci@762: // GEN_FLOW,
marci@762: // PRE_FLOW,
marci@762: // NO_FLOW
marci@762: // };
marci@762:
marci@762: // enum StatusEnum {
marci@762: // AFTER_NOTHING,
marci@762: // AFTER_AUGMENTING,
marci@762: // AFTER_FAST_AUGMENTING,
marci@762: // AFTER_PRE_FLOW_PHASE_1,
marci@762: // AFTER_PRE_FLOW_PHASE_2
marci@762: // };
marci@762:
marci@762: // /// Don not needle this flag only if necessary.
marci@762: // StatusEnum status;
marci@762: // // int number_of_augmentations;
marci@762:
marci@762:
marci@762: // // template<typename IntMap>
marci@762: // // class TrickyReachedMap {
marci@762: // // protected:
marci@762: // // IntMap* map;
marci@762: // // int* number_of_augmentations;
marci@762: // // public:
marci@762: // // TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) :
marci@762: // // map(&_map), number_of_augmentations(&_number_of_augmentations) { }
marci@762: // // void set(const Node& n, bool b) {
marci@762: // // if (b)
marci@762: // // map->set(n, *number_of_augmentations);
marci@762: // // else
marci@762: // // map->set(n, *number_of_augmentations-1);
marci@762: // // }
marci@762: // // bool operator[](const Node& n) const {
marci@762: // // return (*map)[n]==*number_of_augmentations;
marci@762: // // }
marci@762: // // };
marci@762:
marci@762: // MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
marci@762: // FlowMap& _flow) :
marci@762: // g(&_G), s(_s), t(_t), capacity(&_capacity),
marci@762: // flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0),
marci@762: // status(AFTER_NOTHING) { }
marci@762:
marci@762: // ///Runs a maximum flow algorithm.
marci@762:
marci@762: // ///Runs a preflow algorithm, which is the fastest maximum flow
marci@762: // ///algorithm up-to-date. The default for \c fe is ZERO_FLOW.
marci@762: // ///\pre The starting flow must be
marci@762: // /// - a constant zero flow if \c fe is \c ZERO_FLOW,
marci@762: // /// - an arbitary flow if \c fe is \c GEN_FLOW,
marci@762: // /// - an arbitary preflow if \c fe is \c PRE_FLOW,
marci@762: // /// - any map if \c fe is NO_FLOW.
marci@762: // void run(FlowEnum fe=ZERO_FLOW) {
marci@762: // preflow(fe);
marci@762: // }
marci@762:
marci@762:
marci@762: // ///Runs a preflow algorithm.
marci@762:
marci@762: // ///Runs a preflow algorithm. The preflow algorithms provide the
marci@762: // ///fastest way to compute a maximum flow in a directed graph.
marci@762: // ///\pre The starting flow must be
marci@762: // /// - a constant zero flow if \c fe is \c ZERO_FLOW,
marci@762: // /// - an arbitary flow if \c fe is \c GEN_FLOW,
marci@762: // /// - an arbitary preflow if \c fe is \c PRE_FLOW,
marci@762: // /// - any map if \c fe is NO_FLOW.
marci@762: // void preflow(FlowEnum fe) {
marci@762: // preflowPhase1(fe);
marci@762: // preflowPhase2();
marci@762: // }
marci@762: // // Heuristics:
marci@762: // // 2 phase
marci@762: // // gap
marci@762: // // list 'level_list' on the nodes on level i implemented by hand
marci@762: // // stack 'active' on the active nodes on level i
marci@762: // // runs heuristic 'highest label' for H1*n relabels
marci@762: // // runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
marci@762: // // Parameters H0 and H1 are initialized to 20 and 1.
marci@762:
marci@762: // ///Runs the first phase of the preflow algorithm.
marci@762:
marci@762: // ///The preflow algorithm consists of two phases, this method runs the
marci@762: // ///first phase. After the first phase the maximum flow value and a
marci@762: // ///minimum value cut can already be computed, though a maximum flow
marci@762: // ///is net yet obtained. So after calling this method \ref flowValue
marci@762: // ///and \ref actMinCut gives proper results.
marci@762: // ///\warning: \ref minCut, \ref minMinCut and \ref maxMinCut do not
marci@762: // ///give minimum value cuts unless calling \ref preflowPhase2.
marci@762: // ///\pre The starting flow must be
marci@762: // /// - a constant zero flow if \c fe is \c ZERO_FLOW,
marci@762: // /// - an arbitary flow if \c fe is \c GEN_FLOW,
marci@762: // /// - an arbitary preflow if \c fe is \c PRE_FLOW,
marci@762: // /// - any map if \c fe is NO_FLOW.
marci@762: // void preflowPhase1(FlowEnum fe);
marci@762:
marci@762: // ///Runs the second phase of the preflow algorithm.
marci@762:
marci@762: // ///The preflow algorithm consists of two phases, this method runs
marci@762: // ///the second phase. After calling \ref preflowPhase1 and then
marci@762: // ///\ref preflowPhase2 the methods \ref flowValue, \ref minCut,
marci@762: // ///\ref minMinCut and \ref maxMinCut give proper results.
marci@762: // ///\pre \ref preflowPhase1 must be called before.
marci@762: // void preflowPhase2();
marci@762:
marci@762: // /// Returns the maximum value of a flow.
marci@762:
marci@762: // /// Returns the maximum value of a flow, by counting the
marci@762: // /// over-flow of the target node \ref t.
marci@762: // /// It can be called already after running \ref preflowPhase1.
marci@762: // Num flowValue() const {
marci@762: // Num a=0;
marci@762: // FOR_EACH_INC_LOC(InEdgeIt, e, *g, t) a+=(*flow)[e];
marci@762: // FOR_EACH_INC_LOC(OutEdgeIt, e, *g, t) a-=(*flow)[e];
marci@762: // return a;
marci@762: // //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan
marci@762: // }
marci@762:
marci@762: // ///Returns a minimum value cut after calling \ref preflowPhase1.
marci@762:
marci@762: // ///After the first phase of the preflow algorithm the maximum flow
marci@762: // ///value and a minimum value cut can already be computed. This
marci@762: // ///method can be called after running \ref preflowPhase1 for
marci@762: // ///obtaining a minimum value cut.
marci@762: // /// \warning Gives proper result only right after calling \ref
marci@762: // /// preflowPhase1.
marci@762: // /// \todo We have to make some status variable which shows the
marci@762: // /// actual state
marci@762: // /// of the class. This enables us to determine which methods are valid
marci@762: // /// for MinCut computation
marci@762: // template<typename _CutMap>
marci@762: // void actMinCut(_CutMap& M) const {
marci@762: // NodeIt v;
marci@762: // switch (status) {
marci@762: // case AFTER_PRE_FLOW_PHASE_1:
marci@762: // for(g->first(v); g->valid(v); g->next(v)) {
marci@762: // if (level[v] < n) {
marci@762: // M.set(v, false);
marci@762: // } else {
marci@762: // M.set(v, true);
marci@762: // }
marci@762: // }
marci@762: // break;
marci@762: // case AFTER_PRE_FLOW_PHASE_2:
marci@762: // case AFTER_NOTHING:
marci@762: // case AFTER_AUGMENTING:
marci@762: // case AFTER_FAST_AUGMENTING:
marci@762: // minMinCut(M);
marci@762: // break;
marci@762: // // case AFTER_AUGMENTING:
marci@762: // // for(g->first(v); g->valid(v); g->next(v)) {
marci@762: // // if (level[v]) {
marci@762: // // M.set(v, true);
marci@762: // // } else {
marci@762: // // M.set(v, false);
marci@762: // // }
marci@762: // // }
marci@762: // // break;
marci@762: // // case AFTER_FAST_AUGMENTING:
marci@762: // // for(g->first(v); g->valid(v); g->next(v)) {
marci@762: // // if (level[v]==number_of_augmentations) {
marci@762: // // M.set(v, true);
marci@762: // // } else {
marci@762: // // M.set(v, false);
marci@762: // // }
marci@762: // // }
marci@762: // // break;
marci@762: // }
marci@762: // }
marci@762:
marci@762: // ///Returns the inclusionwise minimum of the minimum value cuts.
marci@762:
marci@762: // ///Sets \c M to the characteristic vector of the minimum value cut
marci@762: // ///which is inclusionwise minimum. It is computed by processing
marci@762: // ///a bfs from the source node \c s in the residual graph.
marci@762: // ///\pre M should be a node map of bools initialized to false.
marci@762: // ///\pre \c flow must be a maximum flow.
marci@762: // template<typename _CutMap>
marci@762: // void minMinCut(_CutMap& M) const {
marci@762: // std::queue<Node> queue;
marci@762:
marci@762: // M.set(s,true);
marci@762: // queue.push(s);
marci@762:
marci@762: // while (!queue.empty()) {
marci@762: // Node w=queue.front();
marci@762: // queue.pop();
marci@762:
marci@762: // OutEdgeIt e;
marci@762: // for(g->first(e,w) ; g->valid(e); g->next(e)) {
marci@762: // Node v=g->head(e);
marci@762: // if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
marci@762: // queue.push(v);
marci@762: // M.set(v, true);
marci@762: // }
marci@762: // }
marci@762:
marci@762: // InEdgeIt f;
marci@762: // for(g->first(f,w) ; g->valid(f); g->next(f)) {
marci@762: // Node v=g->tail(f);
marci@762: // if (!M[v] && (*flow)[f] > 0 ) {
marci@762: // queue.push(v);
marci@762: // M.set(v, true);
marci@762: // }
marci@762: // }
marci@762: // }
marci@762: // }
marci@762:
marci@762: // ///Returns the inclusionwise maximum of the minimum value cuts.
marci@762:
marci@762: // ///Sets \c M to the characteristic vector of the minimum value cut
marci@762: // ///which is inclusionwise maximum. It is computed by processing a
marci@762: // ///backward bfs from the target node \c t in the residual graph.
marci@762: // ///\pre M should be a node map of bools initialized to false.
marci@762: // ///\pre \c flow must be a maximum flow.
marci@762: // template<typename _CutMap>
marci@762: // void maxMinCut(_CutMap& M) const {
marci@762:
marci@762: // NodeIt v;
marci@762: // for(g->first(v) ; g->valid(v); g->next(v)) {
marci@762: // M.set(v, true);
marci@762: // }
marci@762:
marci@762: // std::queue<Node> queue;
marci@762:
marci@762: // M.set(t,false);
marci@762: // queue.push(t);
marci@762:
marci@762: // while (!queue.empty()) {
marci@762: // Node w=queue.front();
marci@762: // queue.pop();
marci@762:
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,w) ; g->valid(e); g->next(e)) {
marci@762: // Node v=g->tail(e);
marci@762: // if (M[v] && (*flow)[e] < (*capacity)[e] ) {
marci@762: // queue.push(v);
marci@762: // M.set(v, false);
marci@762: // }
marci@762: // }
marci@762:
marci@762: // OutEdgeIt f;
marci@762: // for(g->first(f,w) ; g->valid(f); g->next(f)) {
marci@762: // Node v=g->head(f);
marci@762: // if (M[v] && (*flow)[f] > 0 ) {
marci@762: // queue.push(v);
marci@762: // M.set(v, false);
marci@762: // }
marci@762: // }
marci@762: // }
marci@762: // }
marci@762:
marci@762: // ///Returns a minimum value cut.
marci@762:
marci@762: // ///Sets \c M to the characteristic vector of a minimum value cut.
marci@762: // ///\pre M should be a node map of bools initialized to false.
marci@762: // ///\pre \c flow must be a maximum flow.
marci@762: // template<typename CutMap>
marci@762: // void minCut(CutMap& M) const { minMinCut(M); }
marci@762:
marci@762: // ///Resets the source node to \c _s.
marci@762:
marci@762: // ///Resets the source node to \c _s.
marci@762: // ///
marci@762: // void resetSource(Node _s) { s=_s; status=AFTER_NOTHING; }
marci@762:
marci@762: // ///Resets the target node to \c _t.
marci@762:
marci@762: // ///Resets the target node to \c _t.
marci@762: // ///
marci@762: // void resetTarget(Node _t) { t=_t; status=AFTER_NOTHING; }
marci@762:
marci@762: // /// Resets the edge map of the capacities to _cap.
marci@762:
marci@762: // /// Resets the edge map of the capacities to _cap.
marci@762: // ///
marci@762: // void resetCap(const CapMap& _cap) { capacity=&_cap; status=AFTER_NOTHING; }
marci@762:
marci@762: // /// Resets the edge map of the flows to _flow.
marci@762:
marci@762: // /// Resets the edge map of the flows to _flow.
marci@762: // ///
marci@762: // void resetFlow(FlowMap& _flow) { flow=&_flow; status=AFTER_NOTHING; }
marci@762:
marci@762:
marci@762: // private:
marci@762:
marci@762: // int push(Node w, VecStack& active) {
marci@762:
marci@762: // int lev=level[w];
marci@762: // Num exc=excess[w];
marci@762: // int newlevel=n; //bound on the next level of w
marci@762:
marci@762: // OutEdgeIt e;
marci@762: // for(g->first(e,w); g->valid(e); g->next(e)) {
marci@762:
marci@762: // if ( (*flow)[e] >= (*capacity)[e] ) continue;
marci@762: // Node v=g->head(e);
marci@762:
marci@762: // if( lev > level[v] ) { //Push is allowed now
marci@762:
marci@762: // if ( excess[v]<=0 && v!=t && v!=s ) {
marci@762: // int lev_v=level[v];
marci@762: // active[lev_v].push(v);
marci@762: // }
marci@762:
marci@762: // Num cap=(*capacity)[e];
marci@762: // Num flo=(*flow)[e];
marci@762: // Num remcap=cap-flo;
marci@762:
marci@762: // if ( remcap >= exc ) { //A nonsaturating push.
marci@762:
marci@762: // flow->set(e, flo+exc);
marci@762: // excess.set(v, excess[v]+exc);
marci@762: // exc=0;
marci@762: // break;
marci@762:
marci@762: // } else { //A saturating push.
marci@762: // flow->set(e, cap);
marci@762: // excess.set(v, excess[v]+remcap);
marci@762: // exc-=remcap;
marci@762: // }
marci@762: // } else if ( newlevel > level[v] ) newlevel = level[v];
marci@762: // } //for out edges wv
marci@762:
marci@762: // if ( exc > 0 ) {
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,w); g->valid(e); g->next(e)) {
marci@762:
marci@762: // if( (*flow)[e] <= 0 ) continue;
marci@762: // Node v=g->tail(e);
marci@762:
marci@762: // if( lev > level[v] ) { //Push is allowed now
marci@762:
marci@762: // if ( excess[v]<=0 && v!=t && v!=s ) {
marci@762: // int lev_v=level[v];
marci@762: // active[lev_v].push(v);
marci@762: // }
marci@762:
marci@762: // Num flo=(*flow)[e];
marci@762:
marci@762: // if ( flo >= exc ) { //A nonsaturating push.
marci@762:
marci@762: // flow->set(e, flo-exc);
marci@762: // excess.set(v, excess[v]+exc);
marci@762: // exc=0;
marci@762: // break;
marci@762: // } else { //A saturating push.
marci@762:
marci@762: // excess.set(v, excess[v]+flo);
marci@762: // exc-=flo;
marci@762: // flow->set(e,0);
marci@762: // }
marci@762: // } else if ( newlevel > level[v] ) newlevel = level[v];
marci@762: // } //for in edges vw
marci@762:
marci@762: // } // if w still has excess after the out edge for cycle
marci@762:
marci@762: // excess.set(w, exc);
marci@762:
marci@762: // return newlevel;
marci@762: // }
marci@762:
marci@762:
marci@762: // void preflowPreproc(FlowEnum fe, VecStack& active,
marci@762: // VecNode& level_list, NNMap& left, NNMap& right)
marci@762: // {
marci@762: // std::queue<Node> bfs_queue;
marci@762:
marci@762: // switch (fe) {
marci@762: // case NO_FLOW: //flow is already set to const zero in this case
marci@762: // case ZERO_FLOW:
marci@762: // {
marci@762: // //Reverse_bfs from t, to find the starting level.
marci@762: // level.set(t,0);
marci@762: // bfs_queue.push(t);
marci@762:
marci@762: // while (!bfs_queue.empty()) {
marci@762:
marci@762: // Node v=bfs_queue.front();
marci@762: // bfs_queue.pop();
marci@762: // int l=level[v]+1;
marci@762:
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,v); g->valid(e); g->next(e)) {
marci@762: // Node w=g->tail(e);
marci@762: // if ( level[w] == n && w != s ) {
marci@762: // bfs_queue.push(w);
marci@762: // Node first=level_list[l];
marci@762: // if ( g->valid(first) ) left.set(first,w);
marci@762: // right.set(w,first);
marci@762: // level_list[l]=w;
marci@762: // level.set(w, l);
marci@762: // }
marci@762: // }
marci@762: // }
marci@762:
marci@762: // //the starting flow
marci@762: // OutEdgeIt e;
marci@762: // for(g->first(e,s); g->valid(e); g->next(e))
marci@762: // {
marci@762: // Num c=(*capacity)[e];
marci@762: // if ( c <= 0 ) continue;
marci@762: // Node w=g->head(e);
marci@762: // if ( level[w] < n ) {
marci@762: // if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
marci@762: // flow->set(e, c);
marci@762: // excess.set(w, excess[w]+c);
marci@762: // }
marci@762: // }
marci@762: // break;
marci@762: // }
marci@762:
marci@762: // case GEN_FLOW:
marci@762: // case PRE_FLOW:
marci@762: // {
marci@762: // //Reverse_bfs from t in the residual graph,
marci@762: // //to find the starting level.
marci@762: // level.set(t,0);
marci@762: // bfs_queue.push(t);
marci@762:
marci@762: // while (!bfs_queue.empty()) {
marci@762:
marci@762: // Node v=bfs_queue.front();
marci@762: // bfs_queue.pop();
marci@762: // int l=level[v]+1;
marci@762:
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,v); g->valid(e); g->next(e)) {
marci@762: // if ( (*capacity)[e] <= (*flow)[e] ) continue;
marci@762: // Node w=g->tail(e);
marci@762: // if ( level[w] == n && w != s ) {
marci@762: // bfs_queue.push(w);
marci@762: // Node first=level_list[l];
marci@762: // if ( g->valid(first) ) left.set(first,w);
marci@762: // right.set(w,first);
marci@762: // level_list[l]=w;
marci@762: // level.set(w, l);
marci@762: // }
marci@762: // }
marci@762:
marci@762: // OutEdgeIt f;
marci@762: // for(g->first(f,v); g->valid(f); g->next(f)) {
marci@762: // if ( 0 >= (*flow)[f] ) continue;
marci@762: // Node w=g->head(f);
marci@762: // if ( level[w] == n && w != s ) {
marci@762: // bfs_queue.push(w);
marci@762: // Node first=level_list[l];
marci@762: // if ( g->valid(first) ) left.set(first,w);
marci@762: // right.set(w,first);
marci@762: // level_list[l]=w;
marci@762: // level.set(w, l);
marci@762: // }
marci@762: // }
marci@762: // }
marci@762:
marci@762:
marci@762: // //the starting flow
marci@762: // OutEdgeIt e;
marci@762: // for(g->first(e,s); g->valid(e); g->next(e))
marci@762: // {
marci@762: // Num rem=(*capacity)[e]-(*flow)[e];
marci@762: // if ( rem <= 0 ) continue;
marci@762: // Node w=g->head(e);
marci@762: // if ( level[w] < n ) {
marci@762: // if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
marci@762: // flow->set(e, (*capacity)[e]);
marci@762: // excess.set(w, excess[w]+rem);
marci@762: // }
marci@762: // }
marci@762:
marci@762: // InEdgeIt f;
marci@762: // for(g->first(f,s); g->valid(f); g->next(f))
marci@762: // {
marci@762: // if ( (*flow)[f] <= 0 ) continue;
marci@762: // Node w=g->tail(f);
marci@762: // if ( level[w] < n ) {
marci@762: // if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
marci@762: // excess.set(w, excess[w]+(*flow)[f]);
marci@762: // flow->set(f, 0);
marci@762: // }
marci@762: // }
marci@762: // break;
marci@762: // } //case PRE_FLOW
marci@762: // }
marci@762: // } //preflowPreproc
marci@762:
marci@762:
marci@762:
marci@762: // void relabel(Node w, int newlevel, VecStack& active,
marci@762: // VecNode& level_list, NNMap& left,
marci@762: // NNMap& right, int& b, int& k, bool what_heur )
marci@762: // {
marci@762:
marci@762: // //FIXME jacint: ez mitol num
marci@762: // // Num lev=level[w];
marci@762: // int lev=level[w];
marci@762:
marci@762: // Node right_n=right[w];
marci@762: // Node left_n=left[w];
marci@762:
marci@762: // //unlacing starts
marci@762: // if ( g->valid(right_n) ) {
marci@762: // if ( g->valid(left_n) ) {
marci@762: // right.set(left_n, right_n);
marci@762: // left.set(right_n, left_n);
marci@762: // } else {
marci@762: // level_list[lev]=right_n;
marci@762: // left.set(right_n, INVALID);
marci@762: // }
marci@762: // } else {
marci@762: // if ( g->valid(left_n) ) {
marci@762: // right.set(left_n, INVALID);
marci@762: // } else {
marci@762: // level_list[lev]=INVALID;
marci@762: // }
marci@762: // }
marci@762: // //unlacing ends
marci@762:
marci@762: // if ( !g->valid(level_list[lev]) ) {
marci@762:
marci@762: // //gapping starts
marci@762: // for (int i=lev; i!=k ; ) {
marci@762: // Node v=level_list[++i];
marci@762: // while ( g->valid(v) ) {
marci@762: // level.set(v,n);
marci@762: // v=right[v];
marci@762: // }
marci@762: // level_list[i]=INVALID;
marci@762: // if ( !what_heur ) {
marci@762: // while ( !active[i].empty() ) {
marci@762: // active[i].pop(); //FIXME: ezt szebben kene
marci@762: // }
marci@762: // }
marci@762: // }
marci@762:
marci@762: // level.set(w,n);
marci@762: // b=lev-1;
marci@762: // k=b;
marci@762: // //gapping ends
marci@762:
marci@762: // } else {
marci@762:
marci@762: // if ( newlevel == n ) level.set(w,n);
marci@762: // else {
marci@762: // level.set(w,++newlevel);
marci@762: // active[newlevel].push(w);
marci@762: // if ( what_heur ) b=newlevel;
marci@762: // if ( k < newlevel ) ++k; //now k=newlevel
marci@762: // Node first=level_list[newlevel];
marci@762: // if ( g->valid(first) ) left.set(first,w);
marci@762: // right.set(w,first);
marci@762: // left.set(w,INVALID);
marci@762: // level_list[newlevel]=w;
marci@762: // }
marci@762: // }
marci@762:
marci@762: // } //relabel
marci@762:
marci@762: // };
marci@762:
marci@762:
marci@762:
marci@762: // template <typename Graph, typename Num, typename CapMap, typename FlowMap>
marci@762: // void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1(FlowEnum fe)
marci@762: // {
marci@762:
marci@762: // int heur0=(int)(H0*n); //time while running 'bound decrease'
marci@762: // int heur1=(int)(H1*n); //time while running 'highest label'
marci@762: // int heur=heur1; //starting time interval (#of relabels)
marci@762: // int numrelabel=0;
marci@762:
marci@762: // bool what_heur=1;
marci@762: // //It is 0 in case 'bound decrease' and 1 in case 'highest label'
marci@762:
marci@762: // bool end=false;
marci@762: // //Needed for 'bound decrease', true means no active nodes are above bound
marci@762: // //b.
marci@762:
marci@762: // int k=n-2; //bound on the highest level under n containing a node
marci@762: // int b=k; //bound on the highest level under n of an active node
marci@762:
marci@762: // VecStack active(n);
marci@762:
marci@762: // NNMap left(*g, INVALID);
marci@762: // NNMap right(*g, INVALID);
marci@762: // VecNode level_list(n,INVALID);
marci@762: // //List of the nodes in level i<n, set to n.
marci@762:
marci@762: // NodeIt v;
marci@762: // for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
marci@762: // //setting each node to level n
marci@762:
marci@762: // if ( fe == NO_FLOW ) {
marci@762: // EdgeIt e;
marci@762: // for(g->first(e); g->valid(e); g->next(e)) flow->set(e,0);
marci@762: // }
marci@762:
marci@762: // switch (fe) { //computing the excess
marci@762: // case PRE_FLOW:
marci@762: // {
marci@762: // NodeIt v;
marci@762: // for(g->first(v); g->valid(v); g->next(v)) {
marci@762: // Num exc=0;
marci@762:
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
marci@762: // OutEdgeIt f;
marci@762: // for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
marci@762:
marci@762: // excess.set(v,exc);
marci@762:
marci@762: // //putting the active nodes into the stack
marci@762: // int lev=level[v];
marci@762: // if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
marci@762: // }
marci@762: // break;
marci@762: // }
marci@762: // case GEN_FLOW:
marci@762: // {
marci@762: // NodeIt v;
marci@762: // for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
marci@762:
marci@762: // Num exc=0;
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
marci@762: // OutEdgeIt f;
marci@762: // for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
marci@762: // excess.set(t,exc);
marci@762: // break;
marci@762: // }
marci@762: // case ZERO_FLOW:
marci@762: // case NO_FLOW:
marci@762: // {
marci@762: // NodeIt v;
marci@762: // for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
marci@762: // break;
marci@762: // }
marci@762: // }
marci@762:
marci@762: // preflowPreproc(fe, active, level_list, left, right);
marci@762: // //End of preprocessing
marci@762:
marci@762:
marci@762: // //Push/relabel on the highest level active nodes.
marci@762: // while ( true ) {
marci@762: // if ( b == 0 ) {
marci@762: // if ( !what_heur && !end && k > 0 ) {
marci@762: // b=k;
marci@762: // end=true;
marci@762: // } else break;
marci@762: // }
marci@762:
marci@762: // if ( active[b].empty() ) --b;
marci@762: // else {
marci@762: // end=false;
marci@762: // Node w=active[b].top();
marci@762: // active[b].pop();
marci@762: // int newlevel=push(w,active);
marci@762: // if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list,
marci@762: // left, right, b, k, what_heur);
marci@762:
marci@762: // ++numrelabel;
marci@762: // if ( numrelabel >= heur ) {
marci@762: // numrelabel=0;
marci@762: // if ( what_heur ) {
marci@762: // what_heur=0;
marci@762: // heur=heur0;
marci@762: // end=false;
marci@762: // } else {
marci@762: // what_heur=1;
marci@762: // heur=heur1;
marci@762: // b=k;
marci@762: // }
marci@762: // }
marci@762: // }
marci@762: // }
marci@762:
marci@762: // status=AFTER_PRE_FLOW_PHASE_1;
marci@762: // }
marci@762:
marci@762:
marci@762:
marci@762: // template <typename Graph, typename Num, typename CapMap, typename FlowMap>
marci@762: // void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase2()
marci@762: // {
marci@762:
marci@762: // int k=n-2; //bound on the highest level under n containing a node
marci@762: // int b=k; //bound on the highest level under n of an active node
marci@762:
marci@762: // VecStack active(n);
marci@762: // level.set(s,0);
marci@762: // std::queue<Node> bfs_queue;
marci@762: // bfs_queue.push(s);
marci@762:
marci@762: // while (!bfs_queue.empty()) {
marci@762:
marci@762: // Node v=bfs_queue.front();
marci@762: // bfs_queue.pop();
marci@762: // int l=level[v]+1;
marci@762:
marci@762: // InEdgeIt e;
marci@762: // for(g->first(e,v); g->valid(e); g->next(e)) {
marci@762: // if ( (*capacity)[e] <= (*flow)[e] ) continue;
marci@762: // Node u=g->tail(e);
marci@762: // if ( level[u] >= n ) {
marci@762: // bfs_queue.push(u);
marci@762: // level.set(u, l);
marci@762: // if ( excess[u] > 0 ) active[l].push(u);
marci@762: // }
marci@762: // }
marci@762:
marci@762: // OutEdgeIt f;
marci@762: // for(g->first(f,v); g->valid(f); g->next(f)) {
marci@762: // if ( 0 >= (*flow)[f] ) continue;
marci@762: // Node u=g->head(f);
marci@762: // if ( level[u] >= n ) {
marci@762: // bfs_queue.push(u);
marci@762: // level.set(u, l);
marci@762: // if ( excess[u] > 0 ) active[l].push(u);
marci@762: // }
marci@762: // }
marci@762: // }
marci@762: // b=n-2;
marci@762:
marci@762: // while ( true ) {
marci@762:
marci@762: // if ( b == 0 ) break;
marci@762:
marci@762: // if ( active[b].empty() ) --b;
marci@762: // else {
marci@762: // Node w=active[b].top();
marci@762: // active[b].pop();
marci@762: // int newlevel=push(w,active);
marci@762:
marci@762: // //relabel
marci@762: // if ( excess[w] > 0 ) {
marci@762: // level.set(w,++newlevel);
marci@762: // active[newlevel].push(w);
marci@762: // b=newlevel;
marci@762: // }
marci@762: // } // if stack[b] is nonempty
marci@762: // } // while(true)
marci@762:
marci@762: // status=AFTER_PRE_FLOW_PHASE_2;
marci@762: // }
marci@762:
marci@762:
marci@762: template <typename Graph, typename Num,
marci@762: typename CapMap=typename Graph::template EdgeMap<Num>,
marci@762: typename FlowMap=typename Graph::template EdgeMap<Num> >
marci@762: class AugmentingFlow {
marci@762: protected:
marci@762: typedef typename Graph::Node Node;
marci@762: typedef typename Graph::NodeIt NodeIt;
marci@762: typedef typename Graph::EdgeIt EdgeIt;
marci@762: typedef typename Graph::OutEdgeIt OutEdgeIt;
marci@762: typedef typename Graph::InEdgeIt InEdgeIt;
marci@762:
marci@762: // typedef typename std::vector<std::stack<Node> > VecStack;
marci@762: // typedef typename Graph::template NodeMap<Node> NNMap;
marci@762: // typedef typename std::vector<Node> VecNode;
marci@762:
marci@762: const Graph* g;
marci@762: Node s;
marci@762: Node t;
marci@762: const CapMap* capacity;
marci@762: FlowMap* flow;
marci@762: // int n; //the number of nodes of G
marci@762: typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
marci@762: //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
marci@762: typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
marci@762: typedef typename ResGW::Edge ResGWEdge;
marci@762: //typedef typename ResGW::template NodeMap<bool> ReachedMap;
marci@762: typedef typename Graph::template NodeMap<int> ReachedMap;
marci@762:
marci@762:
marci@762: //level works as a bool map in augmenting path algorithms and is
marci@762: //used by bfs for storing reached information. In preflow, it
marci@762: //shows the levels of nodes.
marci@762: ReachedMap level;
marci@762:
marci@762: //excess is needed only in preflow
marci@762: // typename Graph::template NodeMap<Num> excess;
marci@762:
marci@762: //fixme
marci@762: // protected:
marci@762: // MaxFlow() { }
marci@762: // void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
marci@762: // FlowMap& _flow)
marci@762: // {
marci@762: // g=&_G;
marci@762: // s=_s;
marci@762: // t=_t;
marci@762: // capacity=&_capacity;
marci@762: // flow=&_flow;
marci@762: // n=_G.nodeNum;
marci@762: // level.set (_G); //kellene vmi ilyesmi fv
marci@762: // excess(_G,0); //itt is
marci@762: // }
marci@762:
marci@762: // constants used for heuristics
marci@762: // static const int H0=20;
marci@762: // static const int H1=1;
marci@762:
marci@762: public:
marci@762:
marci@762: ///Indicates the property of the starting flow.
marci@762:
marci@762: ///Indicates the property of the starting flow. The meanings are as follows:
marci@762: ///- \c ZERO_FLOW: constant zero flow
marci@762: ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
marci@762: ///the sum of the out-flows in every node except the \e source and
marci@762: ///the \e target.
marci@762: ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at
marci@762: ///least the sum of the out-flows in every node except the \e source.
marci@762: ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be
marci@762: ///set to the constant zero flow in the beginning of the algorithm in this case.
marci@762: enum FlowEnum{
marci@762: ZERO_FLOW,
marci@762: GEN_FLOW,
marci@762: PRE_FLOW,
marci@762: NO_FLOW
marci@762: };
marci@762:
marci@762: enum StatusEnum {
marci@762: AFTER_NOTHING,
marci@762: AFTER_AUGMENTING,
marci@762: AFTER_FAST_AUGMENTING,
marci@762: AFTER_PRE_FLOW_PHASE_1,
marci@762: AFTER_PRE_FLOW_PHASE_2
marci@762: };
marci@762:
marci@762: /// Don not needle this flag only if necessary.
marci@762: StatusEnum status;
marci@762: int number_of_augmentations;
marci@762:
marci@762:
marci@762: template<typename IntMap>
marci@762: class TrickyReachedMap {
marci@762: protected:
marci@762: IntMap* map;
marci@762: int* number_of_augmentations;
marci@762: public:
marci@762: TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) :
marci@762: map(&_map), number_of_augmentations(&_number_of_augmentations) { }
marci@762: void set(const Node& n, bool b) {
marci@762: if (b)
marci@762: map->set(n, *number_of_augmentations);
marci@762: else
marci@762: map->set(n, *number_of_augmentations-1);
marci@762: }
marci@762: bool operator[](const Node& n) const {
marci@762: return (*map)[n]==*number_of_augmentations;
marci@762: }
marci@762: };
marci@762:
marci@762: AugmentingFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
marci@762: FlowMap& _flow) :
marci@762: g(&_G), s(_s), t(_t), capacity(&_capacity),
marci@762: flow(&_flow), //n(_G.nodeNum()),
marci@762: level(_G), //excess(_G,0),
marci@762: status(AFTER_NOTHING), number_of_augmentations(0) { }
marci@762:
marci@762: /// Starting from a flow, this method searches for an augmenting path
marci@762: /// according to the Edmonds-Karp algorithm
marci@762: /// and augments the flow on if any.
marci@762: /// The return value shows if the augmentation was succesful.
marci@762: bool augmentOnShortestPath();
marci@762: bool augmentOnShortestPath2();
marci@762:
marci@762: /// Starting from a flow, this method searches for an augmenting blocking
marci@762: /// flow according to Dinits' algorithm and augments the flow on if any.
marci@762: /// The blocking flow is computed in a physically constructed
marci@762: /// residual graph of type \c Mutablegraph.
marci@762: /// The return value show sif the augmentation was succesful.
marci@762: template<typename MutableGraph> bool augmentOnBlockingFlow();
marci@762:
marci@762: /// The same as \c augmentOnBlockingFlow<MutableGraph> but the
marci@762: /// residual graph is not constructed physically.
marci@762: /// The return value shows if the augmentation was succesful.
marci@762: bool augmentOnBlockingFlow2();
marci@762:
marci@762: template<typename _CutMap>
marci@762: void actMinCut(_CutMap& M) const {
marci@762: NodeIt v;
marci@762: switch (status) {
marci@762: case AFTER_PRE_FLOW_PHASE_1:
marci@762: // std::cout << "AFTER_PRE_FLOW_PHASE_1" << std::endl;
marci@762: // for(g->first(v); g->valid(v); g->next(v)) {
marci@762: // if (level[v] < n) {
marci@762: // M.set(v, false);
marci@762: // } else {
marci@762: // M.set(v, true);
marci@762: // }
marci@762: // }
marci@762: break;
marci@762: case AFTER_PRE_FLOW_PHASE_2:
marci@762: // std::cout << "AFTER_PRE_FLOW_PHASE_2" << std::endl;
marci@762: break;
marci@762: case AFTER_NOTHING:
marci@762: // std::cout << "AFTER_NOTHING" << std::endl;
marci@762: minMinCut(M);
marci@762: break;
marci@762: case AFTER_AUGMENTING:
marci@762: // std::cout << "AFTER_AUGMENTING" << std::endl;
marci@775: for(g->first(v); v!=INVALID; ++v) {
marci@762: if (level[v]) {
marci@762: M.set(v, true);
marci@762: } else {
marci@762: M.set(v, false);
marci@762: }
marci@762: }
marci@762: break;
marci@762: case AFTER_FAST_AUGMENTING:
marci@762: // std::cout << "AFTER_FAST_AUGMENTING" << std::endl;
marci@775: for(g->first(v); v!=INVALID; ++v) {
marci@762: if (level[v]==number_of_augmentations) {
marci@762: M.set(v, true);
marci@762: } else {
marci@762: M.set(v, false);
marci@762: }
marci@762: }
marci@762: break;
marci@762: }
marci@762: }
marci@762:
marci@762: template<typename _CutMap>
marci@762: void minMinCut(_CutMap& M) const {
marci@762: std::queue<Node> queue;
marci@762:
marci@762: M.set(s,true);
marci@762: queue.push(s);
marci@762:
marci@762: while (!queue.empty()) {
marci@762: Node w=queue.front();
marci@762: queue.pop();
marci@762:
marci@762: OutEdgeIt e;
marci@775: for(g->first(e,w) ; e!=INVALID; ++e) {
marci@762: Node v=g->head(e);
marci@762: if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
marci@762: queue.push(v);
marci@762: M.set(v, true);
marci@762: }
marci@762: }
marci@762:
marci@762: InEdgeIt f;
marci@775: for(g->first(f,w) ; f!=INVALID; ++f) {
marci@762: Node v=g->tail(f);
marci@762: if (!M[v] && (*flow)[f] > 0 ) {
marci@762: queue.push(v);
marci@762: M.set(v, true);
marci@762: }
marci@762: }
marci@762: }
marci@762: }
marci@762:
marci@762: template<typename _CutMap>
marci@762: void minMinCut2(_CutMap& M) const {
marci@762: ResGW res_graph(*g, *capacity, *flow);
marci@762: BfsIterator<ResGW, _CutMap> bfs(res_graph, M);
marci@762: bfs.pushAndSetReached(s);
marci@762: while (!bfs.finished()) ++bfs;
marci@762: }
marci@762:
marci@762: Num flowValue() const {
marci@762: Num a=0;
marci@777: for (InEdgeIt e(*g, t); e!=INVALID; ++e) a+=(*flow)[e];
marci@777: for (OutEdgeIt e(*g, t); e!=INVALID; ++e) a-=(*flow)[e];
marci@762: return a;
marci@762: //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan
marci@762: }
marci@762:
marci@762: template<typename MapGraphWrapper>
marci@762: class DistanceMap {
marci@762: protected:
marci@762: const MapGraphWrapper* g;
marci@762: typename MapGraphWrapper::template NodeMap<int> dist;
marci@762: public:
marci@762: DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
marci@762: void set(const typename MapGraphWrapper::Node& n, int a) {
marci@762: dist.set(n, a);
marci@762: }
marci@762: int operator[](const typename MapGraphWrapper::Node& n) const {
marci@762: return dist[n];
marci@762: }
marci@762: // int get(const typename MapGraphWrapper::Node& n) const {
marci@762: // return dist[n]; }
marci@762: // bool get(const typename MapGraphWrapper::Edge& e) const {
marci@762: // return (dist.get(g->tail(e))<dist.get(g->head(e))); }
marci@762: bool operator[](const typename MapGraphWrapper::Edge& e) const {
marci@762: return (dist[g->tail(e)]<dist[g->head(e)]);
marci@762: }
marci@762: };
marci@762:
marci@762: };
marci@762:
marci@762:
marci@762:
marci@762: template <typename Graph, typename Num, typename CapMap, typename FlowMap>
marci@762: bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath()
marci@762: {
marci@762: ResGW res_graph(*g, *capacity, *flow);
marci@762: bool _augment=false;
marci@762:
marci@762: //ReachedMap level(res_graph);
marci@777: for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
marci@762: BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
marci@762: bfs.pushAndSetReached(s);
marci@762:
marci@762: typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
marci@762: pred.set(s, INVALID);
marci@762:
marci@762: typename ResGW::template NodeMap<Num> free(res_graph);
marci@762:
marci@762: //searching for augmenting path
marci@762: while ( !bfs.finished() ) {
marci@777: ResGWEdge e=bfs;
marci@775: if (e!=INVALID && bfs.isBNodeNewlyReached()) {
marci@762: Node v=res_graph.tail(e);
marci@762: Node w=res_graph.head(e);
marci@762: pred.set(w, e);
marci@775: if (pred[v]!=INVALID) {
marci@762: free.set(w, std::min(free[v], res_graph.resCap(e)));
marci@762: } else {
marci@762: free.set(w, res_graph.resCap(e));
marci@762: }
marci@762: if (res_graph.head(e)==t) { _augment=true; break; }
marci@762: }
marci@762:
marci@762: ++bfs;
marci@762: } //end of searching augmenting path
marci@762:
marci@762: if (_augment) {
marci@762: Node n=t;
marci@762: Num augment_value=free[t];
marci@775: while (pred[n]!=INVALID) {
marci@762: ResGWEdge e=pred[n];
marci@762: res_graph.augment(e, augment_value);
marci@762: n=res_graph.tail(e);
marci@762: }
marci@762: }
marci@762:
marci@762: status=AFTER_AUGMENTING;
marci@762: return _augment;
marci@762: }
marci@762:
marci@762: template <typename Graph, typename Num, typename CapMap, typename FlowMap>
marci@762: bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath2()
marci@762: {
marci@762: ResGW res_graph(*g, *capacity, *flow);
marci@762: bool _augment=false;
marci@762:
marci@762: if (status!=AFTER_FAST_AUGMENTING) {
marci@777: for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
marci@762: number_of_augmentations=1;
marci@762: } else {
marci@762: ++number_of_augmentations;
marci@762: }
marci@762: TrickyReachedMap<ReachedMap>
marci@762: tricky_reached_map(level, number_of_augmentations);
marci@762: //ReachedMap level(res_graph);
marci@762: // FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
marci@762: BfsIterator<ResGW, TrickyReachedMap<ReachedMap> >
marci@762: bfs(res_graph, tricky_reached_map);
marci@762: bfs.pushAndSetReached(s);
marci@762:
marci@762: typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
marci@762: pred.set(s, INVALID);
marci@762:
marci@762: typename ResGW::template NodeMap<Num> free(res_graph);
marci@762:
marci@762: //searching for augmenting path
marci@762: while ( !bfs.finished() ) {
marci@777: ResGWEdge e=bfs;
marci@775: if (e!=INVALID && bfs.isBNodeNewlyReached()) {
marci@762: Node v=res_graph.tail(e);
marci@762: Node w=res_graph.head(e);
marci@762: pred.set(w, e);
marci@775: if (pred[v]!=INVALID) {
marci@762: free.set(w, std::min(free[v], res_graph.resCap(e)));
marci@762: } else {
marci@762: free.set(w, res_graph.resCap(e));
marci@762: }
marci@762: if (res_graph.head(e)==t) { _augment=true; break; }
marci@762: }
marci@762:
marci@762: ++bfs;
marci@762: } //end of searching augmenting path
marci@762:
marci@762: if (_augment) {
marci@762: Node n=t;
marci@762: Num augment_value=free[t];
marci@775: while (pred[n]!=INVALID) {
marci@762: ResGWEdge e=pred[n];
marci@762: res_graph.augment(e, augment_value);
marci@762: n=res_graph.tail(e);
marci@762: }
marci@762: }
marci@762:
marci@762: status=AFTER_FAST_AUGMENTING;
marci@762: return _augment;
marci@762: }
marci@762:
marci@762:
marci@762: template <typename Graph, typename Num, typename CapMap, typename FlowMap>
marci@762: template<typename MutableGraph>
marci@762: bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow()
marci@762: {
marci@762: typedef MutableGraph MG;
marci@762: bool _augment=false;
marci@762:
marci@762: ResGW res_graph(*g, *capacity, *flow);
marci@762:
marci@762: //bfs for distances on the residual graph
marci@762: //ReachedMap level(res_graph);
marci@777: for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
marci@762: BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
marci@762: bfs.pushAndSetReached(s);
marci@762: typename ResGW::template NodeMap<int>
marci@762: dist(res_graph); //filled up with 0's
marci@762:
marci@762: //F will contain the physical copy of the residual graph
marci@762: //with the set of edges which are on shortest paths
marci@762: MG F;
marci@762: typename ResGW::template NodeMap<typename MG::Node>
marci@762: res_graph_to_F(res_graph);
marci@762: {
marci@762: typename ResGW::NodeIt n;
marci@775: for(res_graph.first(n); n!=INVALID; ++n) {
marci@762: res_graph_to_F.set(n, F.addNode());
marci@762: }
marci@762: }
marci@762:
marci@762: typename MG::Node sF=res_graph_to_F[s];
marci@762: typename MG::Node tF=res_graph_to_F[t];
marci@762: typename MG::template EdgeMap<ResGWEdge> original_edge(F);
marci@762: typename MG::template EdgeMap<Num> residual_capacity(F);
marci@762:
marci@762: while ( !bfs.finished() ) {
marci@777: ResGWEdge e=bfs;
marci@775: if (e!=INVALID) {
marci@762: if (bfs.isBNodeNewlyReached()) {
marci@762: dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
marci@762: typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)],
marci@762: res_graph_to_F[res_graph.head(e)]);
marci@762: original_edge.update();
marci@762: original_edge.set(f, e);
marci@762: residual_capacity.update();
marci@762: residual_capacity.set(f, res_graph.resCap(e));
marci@762: } else {
marci@762: if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) {
marci@762: typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)],
marci@762: res_graph_to_F[res_graph.head(e)]);
marci@762: original_edge.update();
marci@762: original_edge.set(f, e);
marci@762: residual_capacity.update();
marci@762: residual_capacity.set(f, res_graph.resCap(e));
marci@762: }
marci@762: }
marci@762: }
marci@762: ++bfs;
marci@762: } //computing distances from s in the residual graph
marci@762:
marci@762: bool __augment=true;
marci@762:
marci@762: while (__augment) {
marci@762: __augment=false;
marci@762: //computing blocking flow with dfs
marci@762: DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
marci@762: typename MG::template NodeMap<typename MG::Edge> pred(F);
marci@762: pred.set(sF, INVALID);
marci@762: //invalid iterators for sources
marci@762:
marci@762: typename MG::template NodeMap<Num> free(F);
marci@762:
marci@762: dfs.pushAndSetReached(sF);
marci@762: while (!dfs.finished()) {
marci@762: ++dfs;
marci@762: if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
marci@762: if (dfs.isBNodeNewlyReached()) {
marci@777: typename MG::Node v=F.tail(dfs);
marci@777: typename MG::Node w=F.head(dfs);
marci@762: pred.set(w, dfs);
marci@775: if (pred[v]!=INVALID) {
marci@762: free.set(w, std::min(free[v], residual_capacity[dfs]));
marci@762: } else {
marci@762: free.set(w, residual_capacity[dfs]);
marci@762: }
marci@762: if (w==tF) {
marci@762: __augment=true;
marci@762: _augment=true;
marci@762: break;
marci@762: }
marci@762:
marci@762: } else {
marci@762: F.erase(/*typename MG::OutEdgeIt*/(dfs));
marci@762: }
marci@762: }
marci@762: }
marci@762:
marci@762: if (__augment) {
marci@762: typename MG::Node n=tF;
marci@762: Num augment_value=free[tF];
marci@775: while (pred[n]!=INVALID) {
marci@762: typename MG::Edge e=pred[n];
marci@762: res_graph.augment(original_edge[e], augment_value);
marci@762: n=F.tail(e);
marci@762: if (residual_capacity[e]==augment_value)
marci@762: F.erase(e);
marci@762: else
marci@762: residual_capacity.set(e, residual_capacity[e]-augment_value);
marci@762: }
marci@762: }
marci@762:
marci@762: }
marci@762:
marci@762: status=AFTER_AUGMENTING;
marci@762: return _augment;
marci@762: }
marci@762:
marci@762:
marci@762: template <typename Graph, typename Num, typename CapMap, typename FlowMap>
marci@762: bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2()
marci@762: {
marci@762: bool _augment=false;
marci@762:
marci@762: ResGW res_graph(*g, *capacity, *flow);
marci@762:
marci@762: //ReachedMap level(res_graph);
marci@777: for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
marci@762: BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
marci@762:
marci@762: bfs.pushAndSetReached(s);
marci@762: DistanceMap<ResGW> dist(res_graph);
marci@762: while ( !bfs.finished() ) {
marci@777: ResGWEdge e=bfs;
marci@775: if (e!=INVALID && bfs.isBNodeNewlyReached()) {
marci@762: dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
marci@762: }
marci@762: ++bfs;
marci@762: } //computing distances from s in the residual graph
marci@762:
marci@777: //Subgraph containing the edges on some shortest paths
marci@762: ConstMap<typename ResGW::Node, bool> true_map(true);
marci@762: typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>,
marci@762: DistanceMap<ResGW> > FilterResGW;
marci@762: FilterResGW filter_res_graph(res_graph, true_map, dist);
marci@762:
marci@762: //Subgraph, which is able to delete edges which are already
marci@762: //met by the dfs
marci@777: typename FilterResGW::template NodeMap<typename FilterResGW::Edge>
marci@762: first_out_edges(filter_res_graph);
marci@762: typename FilterResGW::NodeIt v;
marci@775: for(filter_res_graph.first(v); v!=INVALID; ++v)
marci@762: {
marci@777: typename FilterResGW::OutEdgeIt e;
marci@777: filter_res_graph.first(e, v);
marci@777: first_out_edges.set(v, e);
marci@762: }
marci@762: typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
marci@777: template NodeMap<typename FilterResGW::Edge> > ErasingResGW;
marci@762: ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
marci@762:
marci@762: bool __augment=true;
marci@762:
marci@762: while (__augment) {
marci@762:
marci@762: __augment=false;
marci@762: //computing blocking flow with dfs
marci@762: DfsIterator< ErasingResGW,
marci@762: typename ErasingResGW::template NodeMap<bool> >
marci@762: dfs(erasing_res_graph);
marci@762: typename ErasingResGW::
marci@777: template NodeMap<typename ErasingResGW::Edge> pred(erasing_res_graph);
marci@762: pred.set(s, INVALID);
marci@762: //invalid iterators for sources
marci@762:
marci@762: typename ErasingResGW::template NodeMap<Num>
marci@762: free1(erasing_res_graph);
marci@762:
marci@762: dfs.pushAndSetReached
marci@777: /// \bug hugo 0.2
marci@762: (typename ErasingResGW::Node
marci@762: (typename FilterResGW::Node
marci@762: (typename ResGW::Node(s)
marci@762: )
marci@762: )
marci@762: );
marci@777:
marci@762: while (!dfs.finished()) {
marci@762: ++dfs;
marci@777: if (typename ErasingResGW::Edge(dfs)!=INVALID)
marci@762: {
marci@762: if (dfs.isBNodeNewlyReached()) {
marci@762:
marci@777: typename ErasingResGW::Node v=erasing_res_graph.tail(dfs);
marci@777: typename ErasingResGW::Node w=erasing_res_graph.head(dfs);
marci@762:
marci@777: pred.set(w, typename ErasingResGW::Edge(dfs));
marci@775: if (pred[v]!=INVALID) {
marci@762: free1.set
marci@762: (w, std::min(free1[v], res_graph.resCap
marci@777: (typename ErasingResGW::Edge(dfs))));
marci@762: } else {
marci@762: free1.set
marci@762: (w, res_graph.resCap
marci@777: (typename ErasingResGW::Edge(dfs)));
marci@762: }
marci@762:
marci@762: if (w==t) {
marci@762: __augment=true;
marci@762: _augment=true;
marci@762: break;
marci@762: }
marci@762: } else {
marci@762: erasing_res_graph.erase(dfs);
marci@762: }
marci@762: }
marci@762: }
marci@762:
marci@762: if (__augment) {
marci@762: typename ErasingResGW::Node
marci@762: n=typename FilterResGW::Node(typename ResGW::Node(t));
marci@762: // typename ResGW::NodeMap<Num> a(res_graph);
marci@762: // typename ResGW::Node b;
marci@762: // Num j=a[b];
marci@762: // typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
marci@762: // typename FilterResGW::Node b1;
marci@762: // Num j1=a1[b1];
marci@762: // typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
marci@762: // typename ErasingResGW::Node b2;
marci@762: // Num j2=a2[b2];
marci@762: Num augment_value=free1[n];
marci@777: while (pred[n]!=INVALID) {
marci@777: typename ErasingResGW::Edge e=pred[n];
marci@762: res_graph.augment(e, augment_value);
marci@762: n=erasing_res_graph.tail(e);
marci@762: if (res_graph.resCap(e)==0)
marci@762: erasing_res_graph.erase(e);
marci@762: }
marci@762: }
marci@762:
marci@762: } //while (__augment)
marci@762:
marci@762: status=AFTER_AUGMENTING;
marci@762: return _augment;
marci@762: }
marci@762:
marci@762:
marci@762: } //namespace hugo
marci@762:
marci@762: #endif //HUGO_AUGMENTING_FLOW_H
marci@762:
marci@762:
marci@762:
marci@762: