Changeset 286:da414906fe21 in lemon for lemon/bfs.h

Timestamp:

09/26/08 12:40:11 (16 years ago)

Author:

Peter Kovacs <kpeter@…>

Branch:

default

Phase:

public

Message:

Improvements related to BFS/DFS/Dijkstra (ticket #96)

• Add run(s,t) function to BfsVisit?.
• Modify run(s,t) functions in the class interfaces to return bool value.
• Bug fix in Dijkstra::start(t) function.
• Improve Dijkstra::currentDist().
• Extend test files to check named class template parameters.
• Doc improvements.

File:

• lemon/bfs.h (modified) (9 diffs)

lemon/bfs.h

@@ -608 +608 @@
     ///
     ///This method runs the %BFS algorithm from the root node(s)
-    ///in order to compute the shortest path to \c dest.
+    ///in order to compute the shortest path to \c t.
     ///
     ///The algorithm computes
-    ///- the shortest path to \c dest,
-    ///- the distance of \c dest from the root(s).
+    ///- the shortest path to \c t,
+    ///- the distance of \c t from the root(s).
     ///
     ///\pre init() must be called and at least one root node should be
@@ -624 +624 @@
     ///  }
     ///\endcode
-    void start(Node dest)
+    void start(Node t)
     {
       bool reach = false;
-      while ( !emptyQueue() && !reach ) processNextNode(dest, reach);
+      while ( !emptyQueue() && !reach ) processNextNode(t, reach);
     }
 
@@ -665 +665 @@
     }
 
-    ///Runs the algorithm from the given node.
+    ///Runs the algorithm from the given source node.
 
     ///This method runs the %BFS algorithm from node \c s
@@ -689 +689 @@
 
     ///This method runs the %BFS algorithm from node \c s
-    ///in order to compute the shortest path to \c t.
-    ///
-    ///\return The length of the shortest <tt>s</tt>--<tt>t</tt> path,
-    ///if \c t is reachable form \c s, \c 0 otherwise.
+    ///in order to compute the shortest path to node \c t
+    ///(it stops searching when \c t is processed).
+    ///
+    ///\return \c true if \c t is reachable form \c s.
     ///
     ///\note Apart from the return value, <tt>b.run(s,t)</tt> is just a
@@ -701 +701 @@
     ///  b.start(t);
     ///\endcode
-    int run(Node s,Node t) {
+    bool run(Node s,Node t) {
       init();
       addSource(s);
       start(t);
-      return reached(t) ? _curr_dist : 0;
+      return reached(t);
     }
 
@@ -1622 +1622 @@
     ///
     /// This method runs the %BFS algorithm from the root node(s)
-    /// in order to compute the shortest path to \c dest.
+    /// in order to compute the shortest path to \c t.
     ///
     /// The algorithm computes
-    /// - the shortest path to \c dest,
-    /// - the distance of \c dest from the root(s).
+    /// - the shortest path to \c t,
+    /// - the distance of \c t from the root(s).
     ///
     /// \pre init() must be called and at least one root node should be
@@ -1638 +1638 @@
     ///   }
     /// \endcode
-    void start(Node dest) {
+    void start(Node t) {
       bool reach = false;
-      while ( !emptyQueue() && !reach ) processNextNode(dest, reach);
+      while ( !emptyQueue() && !reach ) processNextNode(t, reach);
     }
 
@@ -1678 +1678 @@
     }
 
-    /// \brief Runs the algorithm from the given node.
+    /// \brief Runs the algorithm from the given source node.
     ///
     /// This method runs the %BFS algorithm from node \c s
@@ -1697 +1697 @@
       addSource(s);
       start();
+    }
+
+    /// \brief Finds the shortest path between \c s and \c t.
+    ///
+    /// This method runs the %BFS algorithm from node \c s
+    /// in order to compute the shortest path to node \c t
+    /// (it stops searching when \c t is processed).
+    ///
+    /// \return \c true if \c t is reachable form \c s.
+    ///
+    /// \note Apart from the return value, <tt>b.run(s,t)</tt> is just a
+    /// shortcut of the following code.
+    ///\code
+    ///   b.init();
+    ///   b.addSource(s);
+    ///   b.start(t);
+    ///\endcode
+    bool run(Node s,Node t) {
+      init();
+      addSource(s);
+      start(t);
+      return reached(t);
     }