Changeset 1015:e3bb0e118bb4 in lemon-0.x for src/work/marci/lp

Timestamp:

11/20/04 17:12:47 (20 years ago)

Author:

marci

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@1405

Message:

RoadMap? to more general flow algs.

Location:

src/work/marci/lp

Files:

• lp_solver_wrapper.h (modified) (1 diff)
• max_flow_by_lp.cc (modified) (8 diffs)

src/work/marci/lp/lp_solver_wrapper.h

@@ -1 +1 @@
 // -*- c++ -*-
 #ifndef LEMON_LP_SOLVER_WRAPPER_H
-#define LEMON_LP_SOLVER_WRAPPER
+#define LEMON_LP_SOLVER_WRAPPER_H
 
 ///\ingroup misc

src/work/marci/lp/max_flow_by_lp.cc

@@ -13 +13 @@
 #include <lp_solver_wrapper.h>
 
-using namespace lemon;
-
 // Use a DIMACS max flow file as stdin.
 // max_flow_demo < dimacs_max_flow_file
 
-template<typename Edge, typename EdgeIndexMap> 
-class PrimalMap {
-protected:
-  LPSolverWrapper* lp;
-  EdgeIndexMap* edge_index_map;
-public:
-  PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 
-    lp(&_lp), edge_index_map(&_edge_index_map) { }
-  double operator[](Edge e) const { 
-    return lp->getPrimal((*edge_index_map)[e]);
-  }
-};
+using namespace lemon;
+
+namespace lemon {
+
+  template<typename Edge, typename EdgeIndexMap> 
+  class PrimalMap {
+  protected:
+    LPSolverWrapper* lp;
+    EdgeIndexMap* edge_index_map;
+  public:
+    PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 
+      lp(&_lp), edge_index_map(&_edge_index_map) { }
+    double operator[](Edge e) const { 
+      return lp->getPrimal((*edge_index_map)[e]);
+    }
+  };
+
+  // excess: rho-delta
+  template <typename Graph, typename Num,
+            typename Excess=typename Graph::template NodeMap<Num>, 
+            typename LCapMap=typename Graph::template EdgeMap<Num>,
+            typename CapMap=typename Graph::template EdgeMap<Num>,
+            typename FlowMap=typename Graph::template EdgeMap<Num>,
+            typename CostMap=typename Graph::template EdgeMap<Num> >
+  class MinCostGenFlow {
+  protected:
+    const Graph& g;
+    const Excess& excess;
+    const LCapMap& lcapacity;
+    const CapMap& capacity;
+    FlowMap& flow;
+    const CostMap& cost;
+  public:
+    MinCostGenFlow(const Graph& _g, const Excess& _excess, 
+                   const LCapMap& _lcapacity, const CapMap& _capacity, 
+                   FlowMap& _flow, 
+                   const CostMap& _cost) :
+      g(_g), excess(_excess), lcapacity(_lcapacity),
+      capacity(_capacity), flow(_flow), cost(_cost) { }
+    void run() {
+      LPSolverWrapper lp;
+      lp.setMinimize();
+      typedef LPSolverWrapper::ColIt ColIt;
+      typedef LPSolverWrapper::RowIt RowIt;
+      typedef typename Graph::template EdgeMap<ColIt> EdgeIndexMap;
+      EdgeIndexMap edge_index_map(g);
+      PrimalMap<typename Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);
+      for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {
+        ColIt col_it=lp.addCol();
+        edge_index_map.set(e, col_it);
+        if (lcapacity[e]==capacity[e])
+          lp.setColBounds(col_it, LPX_FX, lcapacity[e], capacity[e]);
+        else 
+          lp.setColBounds(col_it, LPX_DB, lcapacity[e], capacity[e]);
+        lp.setObjCoef(col_it, cost[e]);
+      }
+      for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {
+        typename Graph::template EdgeMap<Num> coeffs(g, 0);
+        for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)
+        coeffs.set(e, coeffs[e]+1);
+        for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 
+        coeffs.set(e, coeffs[e]-1);
+        RowIt row_it=lp.addRow();
+        typename std::vector< std::pair<ColIt, double> > row;
+        //std::cout << "node:" <<g.id(n)<<std::endl;
+        for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {
+          if (coeffs[e]!=0) {
+            //std::cout << " edge:" <<g.id(e)<<" "<<coeffs[e];
+            row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));
+          }
+        }
+        //std::cout << std::endl;
+        lp.setRowCoeffs(row_it, row.begin(), row.end());
+        lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);
+      }
+      lp.solveSimplex();
+      //std::cout << lp.colNum() << std::endl;
+      //std::cout << lp.rowNum() << std::endl;
+      //std::cout << "flow value: "<< lp.getObjVal() << std::endl;
+      for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) 
+      flow.set(e, lp_flow[e]);
+    }
+  };
+
+}
 
 int main(int, char **) {
@@ -36 +107 @@
   typedef SmartGraph Graph;
   typedef Graph::Node Node;
+  typedef Graph::Edge Edge;
   typedef Graph::EdgeIt EdgeIt;
 
@@ -61 +133 @@
     max_flow_test.minCut(cut);
 
-    for (Graph::EdgeIt e(g); e!=INVALID; ++e) {
+    for (EdgeIt e(g); e!=INVALID; ++e) {
       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
         std::cout << "Slackness does not hold!" << std::endl;
@@ -96 +168 @@
   {
     std::cout << "physical blocking flow augmentation ..." << std::endl;
-    for (Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);
+    for (EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);
     ts.reset();
     int i=0;
@@ -104 +176 @@
     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
 
-    for (Graph::EdgeIt e(g); e!=INVALID; ++e) {
+    for (EdgeIt e(g); e!=INVALID; ++e) {
       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
         std::cout << "Slackness does not hold!" << std::endl;
@@ -125 +197 @@
   {
     std::cout << "on-the-fly blocking flow augmentation ..." << std::endl;
-    for (Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);
+    for (EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);
     ts.reset();
     int i=0;
@@ -133 +205 @@
     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
 
-    for (Graph::EdgeIt e(g); e!=INVALID; ++e) {
+    for (EdgeIt e(g); e!=INVALID; ++e) {
       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
         std::cout << "Slackness does not hold!" << std::endl;
@@ -178 +250 @@
 
   ts.reset();
-  LPSolverWrapper lp;
-  lp.setMaximize();
-  typedef LPSolverWrapper::ColIt ColIt;
-  typedef LPSolverWrapper::RowIt RowIt;
-  typedef Graph::EdgeMap<ColIt> EdgeIndexMap;
-  EdgeIndexMap edge_index_map(g);
-  PrimalMap<Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);
-  for (Graph::EdgeIt e(g); e!=INVALID; ++e) {
-    ColIt col_it=lp.addCol();
-    edge_index_map.set(e, col_it);
-    lp.setColBounds(col_it, LPX_DB, 0.0, cap[e]);
-  }
-  for (Graph::NodeIt n(g); n!=INVALID; ++n) {
-    if (n!=s) {
-      //hurokelek miatt
-      Graph::EdgeMap<int> coeffs(g, 0);
-      for (Graph::InEdgeIt e(g, n); e!=INVALID; ++e) 
-        coeffs.set(e, coeffs[e]+1);
-      for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 
-        coeffs.set(e, coeffs[e]-1);
-      if (n==t) {
-        for (Graph::EdgeIt e(g); e!=INVALID; ++e) {
-          if (coeffs[e]!=0) 
-            lp.setObjCoef(edge_index_map[e], coeffs[e]);
-        }
-      } else  {
-        RowIt row_it=lp.addRow();
-        std::vector< std::pair<ColIt, double> > row;
-        for (Graph::EdgeIt e(g); e!=INVALID; ++e) {
-          if (coeffs[e]!=0) 
-            row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));
-        }       
-        lp.setRowCoeffs(row_it, row.begin(), row.end());
-        lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);
-      }
-    }
-  }
-  lp.solveSimplex();
-  std::cout << "flow value: "<< lp.getObjVal() << std::endl;
+
+  Edge e=g.addEdge(t, s);
+  Graph::EdgeMap<int> cost(g, 0);
+  cost.set(e, -1);
+  cap.set(e, 10000);
+  typedef ConstMap<Node, int> Excess;
+  Excess excess(0);
+  typedef ConstMap<Edge, int> LCap;
+  LCap lcap(0);
+
+  MinCostGenFlow<Graph, int, Excess, LCap> 
+    min_cost(g, excess, lcap, cap, flow, cost); 
+  min_cost.run();
+
   std::cout << "elapsed time: " << ts << std::endl;
-
-  return 0;
+  std::cout << "flow value: "<< flow[e] << std::endl;
 }