marci@423: // -*- c++ -*-
marci@423: #ifndef HUGO_DIMACS_H
marci@423: #define HUGO_DIMACS_H
marci@423: 
marci@423: #include <iostream>
marci@423: #include <string>
marci@423: #include <vector>
marci@423: 
klao@442: /// \file
klao@442: /// \brief Dimacs file format reader.
klao@427: 
marci@423: namespace hugo {
marci@423: 
klao@427:   /// Dimacs flow file format reader function.
marci@423: 
marci@423:   /// This function reads a flow instance from dimacs flow format.
klao@427:   /// At the beginning \c g is cleared by \c g.clear().
klao@427:   /// If the data coming from \c is is a max flow problem instance, then 
klao@427:   /// \c s and \c t will be respectively the source and target nodes 
marci@423:   /// and \c capacity will contain the edge capacities.
klao@427:   /// If the data is a shortest path problem instance then \c s will be the 
klao@427:   /// source node and \c capacity will contain the edge lengths.
marci@423:   template<typename Graph, typename CapacityMap>
marci@423:   void readDimacsMaxFlow(std::istream& is, Graph &g, typename Graph::Node &s, typename Graph::Node &t, CapacityMap& capacity) {
marci@423:     g.clear();
marci@423:     int cap;
marci@423:     char d;
marci@423:     std::string problem;
marci@423:     char c;
marci@423:     int i, j;
marci@423:     std::string str;
marci@423:     int n, m; 
marci@423:     typename Graph::Edge e;
marci@423:     std::vector<typename Graph::Node> nodes;
marci@423:     while (is>>c) {
marci@423:       switch (c) {
marci@423:       case 'c': //comment
marci@423: 	getline(is, str);
marci@423: 	break;
marci@423:       case 'p': //problem definition
marci@423: 	is >> problem >> n >> m;
marci@423: 	getline(is, str);
marci@423: 	nodes.resize(n+1);
marci@423: 	for (int k=1; k<=n; ++k) nodes[k]=g.addNode();
marci@423: 	break;
marci@423:       case 'n': //node definition
marci@423: 	if (problem=="sp") { //shortest path problem
marci@423: 	  is >> i;
marci@423: 	  getline(is, str);
marci@423: 	  s=nodes[i];
marci@423: 	}
marci@423: 	if (problem=="max") { //max flow problem
marci@423: 	  is >> i >> d;
marci@423: 	  getline(is, str);
marci@423: 	  if (d=='s') s=nodes[i];
marci@423: 	  if (d=='t') t=nodes[i];
marci@423: 	}
marci@423: 	break;
marci@423:       case 'a':
marci@423: 	is >> i >> j >> cap;
marci@423: 	getline(is, str);
marci@423: 	e=g.addEdge(nodes[i], nodes[j]);
marci@423: 	capacity.update();
marci@423: 	capacity.set(e, cap);
marci@423: 	break;
marci@423:       }
marci@423:     }
marci@423:   }
marci@423:   
marci@423: } //namespace hugo
marci@423: 
marci@423: #endif //HUGO_DIMACS_H