src/work/marci/bfsit_vs_byhand.cc
author jacint
Thu, 22 Apr 2004 15:58:08 +0000
changeset 375 d9a58896ab43
parent 359 8cc53a6b1e61
child 389 770cc1f4861f
permissions -rw-r--r--
(none)
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// -*- c++ -*-
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#include <iostream>
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#include <fstream>
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#include <list_graph.h>
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#include <smart_graph.h>
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#include <dimacs.h>
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#include <time_measure.h>
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#include <for_each_macros.h>
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#include <bfs_iterator.h>
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using namespace hugo;
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int main() {
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  typedef ListGraph Graph; 
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  typedef Graph::Node Node;
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  typedef Graph::NodeIt NodeIt;
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  typedef Graph::Edge Edge;
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  typedef Graph::EdgeIt EdgeIt;
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  typedef Graph::OutEdgeIt OutEdgeIt;
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  Graph G;
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  Node s, t;
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  Graph::EdgeMap<int> cap(G);
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  readDimacsMaxFlow(std::cin, G, s, t, cap);
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  Graph::NodeMap<OutEdgeIt> pred(G);
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  Timer ts;
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  {
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    ts.reset();
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    Graph::NodeMap<bool> reached(G);
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    reached.set(s, true);
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    pred.set(s, INVALID);
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    std::queue<Node> bfs_queue;
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    bfs_queue.push(t);
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    while (!bfs_queue.empty()) {
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      Node v=bfs_queue.front();	
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      bfs_queue.pop();
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      OutEdgeIt e;
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      for(G.first(e,v); G.valid(e); G.next(e)) {
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	Node w=G.head(e);
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	if (!reached[w]) {
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	  bfs_queue.push(w);
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	  reached.set(w, true);
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	  pred.set(w, e);
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	}
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      }
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    }
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    std::cout << ts << std::endl;
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  }
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  {
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    ts.reset();      
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    BfsIterator< Graph, Graph::NodeMap<bool> > bfs(G);
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    bfs.pushAndSetReached(s);
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    pred.set(s, INVALID);
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    while (!bfs.finished()) { 
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      ++bfs; 
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      if (G.valid(bfs) && bfs.isBNodeNewlyReached()) 
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	pred.set(bfs.bNode(), bfs);
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    }
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    std::cout << ts << std::endl;
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  }
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  return 0;
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}