# HG changeset patch
# User alpar
# Date 1090944261 0
# Node ID aa700e5c47b552830b6c0c32470214fb3a6dbdcc
# Parent  7237eaaf5d84c86b168dc1c572a218357f280ee8
A very flexible bfs function using named parameters and impicit map types.

diff -r 7237eaaf5d84 -r aa700e5c47b5 src/work/alpar/bfs-named-param.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/alpar/bfs-named-param.cc	Tue Jul 27 16:04:21 2004 +0000
@@ -0,0 +1,159 @@
+// -*- mode:C++ -*-
+
+#include <hugo/smart_graph.h>
+#include <hugo/maps.h>
+#include <vector>
+
+using namespace hugo;
+
+struct _BFS_DEFAULT_VIS {};
+struct _BFS_CUSTOM_VIS {};
+
+template<class GT,class VT,class DVT,class PNT,class PET,class PT >
+class _BFS 
+{
+ public:
+  typedef GT Graph;
+  typedef VT Visited;
+  typedef PNT PredNode;
+  typedef PET PredEdge;
+  typedef PT Priority;
+  //  typedef QDT QueueData;
+  
+  typedef typename Graph::Node Node;
+  typedef typename Graph::OutEdgeIt OutEdgeIt;
+
+  typedef DVT DefaultVisitedTag;
+  
+  const Graph &_graph;
+
+  Node _source;
+  
+  Visited *_visited;
+  PredNode _predNode;
+  PredEdge _predEdge;
+  Priority _priority;
+
+  _BFS(const Graph &g,
+       Node s,
+       Visited *v,
+       PredNode &pn,
+       PredEdge &pe,
+       Priority &pr) :_graph(g), _source(s),
+		     _visited(v), 
+		     _predNode(pn), _predEdge(pe), _priority(pr) { }
+
+  
+  int run(const _BFS_CUSTOM_VIS &) 
+  {
+    using namespace std;
+    
+    int N=_graph.nodeNum();
+    vector<Node> Q(N);
+    int Qh=0;
+    int Qt=0;
+    
+    for(typename Graph::NodeIt n(_graph);_graph.valid(n);_graph.next(n))
+      _visited->set(n,false);
+
+    Q[Qh++]=_source;
+    _visited->set(_source,true);
+    do {
+      Node m;
+      Node n=Q[Qt++];
+      for(OutEdgeIt e(_graph,n);_graph.valid(e);_graph.next(e))
+	if(!(*_visited)[m=_graph.head(e)]) {
+	  Q[Qh++]=m;
+	  _visited->set(m,true);
+	  _predNode.set(m,n);
+	  _predEdge.set(m,e);	  
+	}
+    } while(Qt!=Qh);
+
+    return 1; //Why return 1?
+  }
+  int run(const _BFS_DEFAULT_VIS &) 
+  {
+    _visited= new Visited(_graph);
+    int r = run(_BFS_CUSTOM_VIS());
+    delete _visited;
+    return r;
+  }
+  int run() { return run(DefaultVisitedTag());}
+
+  template<class T> _BFS<Graph,T,_BFS_CUSTOM_VIS,PredNode,PredEdge,Priority>
+  setVisitMap(T &t)
+  {
+    return _BFS<Graph,T,_BFS_CUSTOM_VIS,PredNode,PredEdge,Priority>
+      (_graph,_source,&t,_predNode,_predEdge,_priority);
+  }
+
+  template<class T>
+  _BFS<Graph,Visited,_BFS_CUSTOM_VIS,T,PredEdge,Priority>
+  setPredNodeMap(T &t)
+  {
+    return _BFS<Graph,Visited,_BFS_CUSTOM_VIS,T,PredEdge,Priority>
+      (_graph,_source,
+       _visited,
+       t,_predEdge,_priority);
+  }
+
+  template<class T>
+  _BFS<Graph,Visited,_BFS_CUSTOM_VIS,PredNode,T,Priority>
+  setPredEdgeMap(T &t)
+  {
+    return _BFS<Graph,Visited,_BFS_CUSTOM_VIS,PredNode,T,Priority>
+      (_graph,_source,
+       _visited,
+      _predNode,t,_priority);
+  }
+
+  _BFS<Graph,Visited,_BFS_CUSTOM_VIS,PredNode,PredEdge,Priority>
+  setNothing()
+  {
+    return _BFS<Graph,Visited,_BFS_CUSTOM_VIS,PredNode,PredEdge,Priority>
+      (_graph,_source,
+       _visited,
+       _predNode,_predEdge,_priority);
+  }
+};
+
+
+template<class G>
+_BFS<G,
+     typename G::template NodeMap<bool>,
+     _BFS_DEFAULT_VIS,
+     NullMap<typename G::Node,typename G::Node>,
+     NullMap<typename G::Node,typename G::Edge>,
+     NullMap<typename G::Node,int> >
+bfs(const G &g,typename G::Node s)
+{
+  //  typename G::template NodeMap<bool> v(g);
+
+  return _BFS < G,
+    typename G::template NodeMap<bool>,
+    _BFS_DEFAULT_VIS,
+     NullMap<typename G::Node,typename G::Node>,
+     NullMap<typename G::Node,typename G::Edge>,
+    NullMap<typename G::Node,int> >
+    (g,s,
+     (typename G::template NodeMap<bool>*)(NULL),
+     *((NullMap<typename G::Node,typename G::Node>*)(NULL)),
+     *((NullMap<typename G::Node,typename G::Edge> *)(NULL)),
+     *((NullMap<typename G::Node,int> *)(NULL))
+     );
+}
+
+
+int main()
+{
+  SmartGraph G;
+  SmartGraph::NodeIt n(G);
+  SmartGraph::NodeMap<SmartGraph::Node> m(G);
+  SmartGraph::NodeMap<SmartGraph::Edge> em(G);
+  
+  bfs(G,n).run();
+  bfs(G,n).setPredNodeMap(m).run();
+  bfs(G,n).setPredNodeMap(m).setPredEdgeMap(em).run();
+
+}