1.1 --- a/src/lemon/full_graph.h	Sat Nov 13 12:24:01 2004 +0000
     1.2 +++ b/src/lemon/full_graph.h	Sat Nov 13 12:53:28 2004 +0000
     1.3 @@ -78,8 +78,8 @@
     1.4      ///\sa id(Edge)
     1.5      int maxId(Edge = INVALID) const { return EdgeNum-1; }
     1.6  
     1.7 -    Node tail(Edge e) const { return e.id % NodeNum; }
     1.8 -    Node head(Edge e) const { return e.id / NodeNum; }
     1.9 +    Node source(Edge e) const { return e.id % NodeNum; }
    1.10 +    Node target(Edge e) const { return e.id / NodeNum; }
    1.11  
    1.12  
    1.13      /// Node ID.
    1.14 @@ -136,12 +136,12 @@
    1.15        friend class FullGraphBase;
    1.16        
    1.17      protected:
    1.18 -      int id;  // NodeNum * head + tail;
    1.19 +      int id;  // NodeNum * target + source;
    1.20  
    1.21        Edge(int _id) : id(_id) {}
    1.22  
    1.23 -      Edge(const FullGraphBase& _graph, int tail, int head) 
    1.24 -	: id(_graph.NodeNum * head+tail) {}
    1.25 +      Edge(const FullGraphBase& _graph, int source, int target) 
    1.26 +	: id(_graph.NodeNum * target+source) {}
    1.27      public:
    1.28        Edge() { }
    1.29        Edge (Invalid) { id = -1; }
    1.30 @@ -250,14 +250,14 @@
    1.31      ///\sa id(Edge)
    1.32      int maxId(Edge = INVALID) const { return EdgeNum-1; }
    1.33  
    1.34 -    Node tail(Edge e) const { 
    1.35 +    Node source(Edge e) const { 
    1.36        /// \todo we may do it faster
    1.37        return ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2; 
    1.38      }
    1.39  
    1.40 -    Node head(Edge e) const { 
    1.41 -      int tail = ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2;;
    1.42 -      return e.id - (tail) * (tail - 1) / 2; 
    1.43 +    Node target(Edge e) const { 
    1.44 +      int source = ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2;;
    1.45 +      return e.id - (source) * (source - 1) / 2; 
    1.46      }
    1.47  
    1.48  
    1.49 @@ -315,12 +315,12 @@
    1.50        friend class UndirFullGraphBase;
    1.51        
    1.52      protected:
    1.53 -      int id;  // NodeNum * head + tail;
    1.54 +      int id;  // NodeNum * target + source;
    1.55  
    1.56        Edge(int _id) : id(_id) {}
    1.57  
    1.58 -      Edge(const UndirFullGraphBase& _graph, int tail, int head) 
    1.59 -	: id(_graph.NodeNum * head+tail) {}
    1.60 +      Edge(const UndirFullGraphBase& _graph, int source, int target) 
    1.61 +	: id(_graph.NodeNum * target+source) {}
    1.62      public:
    1.63        Edge() { }
    1.64        Edge (Invalid) { id = -1; }
    1.65 @@ -351,10 +351,10 @@
    1.66  
    1.67      /// \todo with specialized iterators we can make faster iterating
    1.68      void nextOut(Edge& e) const {
    1.69 -      int tail = ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2;;
    1.70 -      int head = e.id - (tail) * (tail - 1) / 2; 
    1.71 -      ++head;
    1.72 -      e.id = head < tail ? tail * (tail - 1) / 2 + head : -1;
    1.73 +      int source = ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2;;
    1.74 +      int target = e.id - (source) * (source - 1) / 2; 
    1.75 +      ++target;
    1.76 +      e.id = target < source ? source * (source - 1) / 2 + target : -1;
    1.77      }
    1.78  
    1.79      void firstIn(Edge& edge, const Node& node) const {
    1.80 @@ -362,10 +362,10 @@
    1.81      }
    1.82      
    1.83      void nextIn(Edge& e) const {
    1.84 -      int tail = ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2;;
    1.85 -      int head = e.id - (tail) * (tail - 1) / 2; ++head;
    1.86 -      ++tail;
    1.87 -      e.id = tail < NodeNum ? tail * (tail - 1) / 2 + head : -1;
    1.88 +      int source = ((int)sqrt((double)(1 + 8 * e.id)) + 1) / 2;;
    1.89 +      int target = e.id - (source) * (source - 1) / 2; ++target;
    1.90 +      ++source;
    1.91 +      e.id = source < NodeNum ? source * (source - 1) / 2 + target : -1;
    1.92      }
    1.93  
    1.94    };