source: lemon-0.x/src/work/marci/bfsit_vs_byhand.cc @ 941:186aa53d2802

// -*- c++ -*-
#include <iostream>
#include <fstream>

#include <sage_graph.h>
#include <lemon/smart_graph.h>
#include <lemon/dimacs.h>
#include <lemon/time_measure.h>
//#include <lemon/for_each_macros.h>
#include <bfs_dfs.h>

using namespace lemon;

using std::cout;
using std::endl;

int main() {
  typedef SageGraph Graph; 
  typedef Graph::Node Node;
  typedef Graph::NodeIt NodeIt;
  typedef Graph::Edge Edge;
  typedef Graph::EdgeIt EdgeIt;
  typedef Graph::OutEdgeIt OutEdgeIt;

  Graph g;
  //Node s;
  //Graph::EdgeMap<int> cap(g);
  //readDimacsMaxFlow(std::cin, g, s, t, cap);
  readDimacs(std::cin, g);
  NodeIt s;
  g.first(s);

  cout << g.nodeNum() << endl;
  cout << g.edgeNum() << endl;

  Graph::NodeMap<Edge> pred(g);
  cout << "iteration time of bfs written by hand..." << endl;
  Timer ts;
  {
    ts.reset();
    Graph::NodeMap<bool> reached(g);
    reached.set(s, true);
    pred.set(s, INVALID);
    std::queue<Node> bfs_queue;
    bfs_queue.push(s);
    while (!bfs_queue.empty()) {
      Node v=bfs_queue.front(); 
      bfs_queue.pop();
      OutEdgeIt e;
      for(g.first(e,v); g.valid(e); g.next(e)) {
        Node w=g.head(e);
        if (!reached[w]) {
          bfs_queue.push(w);
          reached.set(w, true);
          pred.set(w, e);
        }
      }
    }

    std::cout << ts << std::endl;
  }

  cout << "iteration time with bfs iterator..." << endl;
  {
    ts.reset();      
    BfsIterator< Graph, Graph::NodeMap<bool> > bfs(g);
    bfs.pushAndSetReached(s);
    pred.set(s, INVALID);
    while (!bfs.finished()) { 
      ++bfs; 
      if (g.valid(bfs) && bfs.isBNodeNewlyReached()) 
        pred.set(bfs.head(), Graph::Edge(bfs));
    }
    std::cout << ts << std::endl;
  }

  return 0;
}