flow.cc

#include <scil/scil.h>
#include <LEDA/graph.h>
#include <scil/constraints/flow.h>

using namespace SCIL;
using namespace LEDA;

class FLOW::flow_balance : public cons_obj {
private:
  graph& G;
  node v;
  scil_map<edge>& VM;
  row vv;
  
public:
  flow_balance(graph& G_, node& v_, 
               scil_map<edge>& VM_, row vv_)
    : cons_obj(Equal, 0), G(G_), 
      v(v_), VM(VM_), vv(vv_) {
  };

  virtual void non_zero_entries(row& r) {
    edge e;
    forall_out_edges(e, v) {
      r+=VM(e);
    };
    forall_in_edges(e, v) {
      r-=VM(e);
    }
    r-=vv;
  };

  virtual ~flow_balance() {};
};


FLOW::FLOW(graph& G_, scil_map<node>& D_, scil_map<edge>& VM_) :
  /*{\Mcreate The constraint FLOWs adds the flow preservation constraints for all
    nodes, i.e.~
    $\sum_{e \in \delta^+(v)} x_e - \sum_{e \in \delta^-(v)} x_e = x_v $.\\
    For a demo see: production.}*/
  G(G_), D(D_), VM(VM_) {
};

void FLOW::init(subproblem& S) {
  node v;
  forall_nodes(v, G) {
    cout<<"Add\n";
    S.add_basic_constraint(new flow_balance(G, v, VM, D(v)));
    cout<<"Suceed\n";
  }
};

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