marci@455: // -*- c++ -*-
marci@455: #ifndef HUGO_BIPARTITE_GRAPHS_H
marci@455: #define HUGO_BIPARTITE_GRAPHS_H
marci@455: 
marci@455: #include <bfs_iterator.h>
marci@455: #include <for_each_macros.h>
marci@455: 
marci@455: namespace hugo {
marci@455: 
marci@455:   /// This function eat a read-write \c BoolMap& bool_map, 
marci@455:   /// which have to work well up 
marci@455:   /// to its \c set and \c operator[]() method. Thus we have to deal 
marci@455:   /// very carefully with an uninitialized \c IterableBoolMap.
marci@455:   template<typename Graph, typename BoolMap> 
marci@455:   bool isBipartite(const Graph& g, BoolMap& bool_map) {
marci@455:     typedef typename Graph::template NodeMap<bool> ReachedMap;
marci@455:     ReachedMap reached(g/*, false*/);
marci@455:     BfsIterator<Graph, ReachedMap> bfs(g, reached);
marci@455:     FOR_EACH_LOC(typename Graph::NodeIt, n, g) {
marci@455:       if (!reached[n]) {
marci@455: 	bfs.pushAndSetReached(n);
marci@455: 	bool_map.set(n, false) {
marci@455: 	  while (!bfs.finished()) {
marci@455: 	    if (bfs.isBNodeNewlyReached()) {
marci@455: 	      bool_map.set(bfs.bNode())=!bfs.aNode();
marci@455: 	    } else {
marci@455: 	      if (bool_map[bfs.bNode()]==bool_map[bfs.aNode()]) {
marci@455: 		return false;
marci@455: 	      }
marci@455: 	    }
marci@455: 	    ++bfs;
marci@455: 	  }
marci@455: 	}
marci@455:       }
marci@455:     }
marci@455:     return true;
marci@455:   }
marci@540: 
marci@540:   /// experimental topsort, 
marci@540:   /// I think the final version will work as an iterator
marci@540:   template<typename Graph> 
marci@540:   void topSort(Graph& g, std::list<typename Graph::Node>& l) {
marci@540:     l.clear();
marci@540:     typedef typename Graph::template NodeMap<bool> ReachedMap;
marci@540:     ReachedMap reached(g/*, false*/);
marci@540:     DfsIterator<Graph, ReachedMap> dfs(g, reached);
marci@540:     FOR_EACH_LOC(typename Graph::NodeIt, n, g) {
marci@540:       if (!reached[n]) {
marci@540: 	dfs.pushAndSetReached(n);
marci@540: 	while (!bfs.finished()) {
marci@540: 	  if (bfs.isANodeExamined()) {
marci@540: 	    l.push_back(bfs.aNode());
marci@540: 	  }
marci@540: 	  ++bfs;
marci@540: 	}
marci@540:       }
marci@540:     }
marci@540:   }
marci@455: }
marci@455: #endif //HUGO_BIPARTITE_GRAPHS_H