X-Git-Url: https://www.fleuret.org/cgi-bin/gitweb/gitweb.cgi?p=mtp.git;a=blobdiff_plain;f=mtp_graph.h;h=9f50ae48f1f7d8d97dedc64d03bbcb96d2713e37;hp=5842671223347d25a924141723be11f63942f2e9;hb=c752952df0dd1d781ec80f25c4b9418bddac1b9e;hpb=2b3a2e10ec226f1610b9c39abd20f0899a34a652

diff --git a/mtp_graph.h b/mtp_graph.h
index 5842671..9f50ae4 100644
--- a/mtp_graph.h
+++ b/mtp_graph.h
@@ -37,6 +37,10 @@ class Vertex;
 class Edge;
 
 class MTPGraph {
+  // Set the distance_from_source fields to the number of DP
+  // iterations needed to update it. Abort if the graph is not a DAG.
+  int compute_dp_ranks();
+
   // Uses the estimated vertex distances to the source to make all the
   // edge lengths positive, resulting in an identical added value to
   // all the paths from the same initial node to the same final node
@@ -49,16 +53,13 @@ class MTPGraph {
   // the total correction when compiled in VERBOSE mode.
   void force_positivized_lengths();
 
-  void decrease_distance_in_heap(Vertex *v);
-  void increase_distance_in_heap(Vertex *v);
-
-  // Visit the vertices according to _dp_order and simply update their
-  // distance to the source
-  void dp_distance_propagation();
+  // Visit the vertices according to _dp_order and update their
+  // distance from the source
+  void dp_compute_distances();
 
   // Set in every vertex pred_edge_toward_source correspondingly to
-  // the path of shortest length. The current implementation is not
-  // Dijkstra's!
+  // the path of shortest length. The current implementation is
+  // Dijkstra with a Binary Heap (and not with Fibonnaci heap (yet))
   void find_shortest_path();
 
   // Follows the path starting on edge e and returns the number of
@@ -66,22 +67,18 @@ class MTPGraph {
   // nodes met along the path, and computes path->length properly.
   int retrieve_one_path(Edge *e, Path *path);
 
-  // Returns if the graph is a DAG, and set the last_change field of
-  // each vertex to the maximum number of iterations required to reach
-  // it
-  int is_dag();
-
   int _nb_vertices, _nb_edges;
   Vertex *_source, *_sink;
 
   Edge *_edges;
   Vertex *_vertices;
 
-  // For the shortest path search
-
+  // For Dijkstra
   Vertex **_heap;
   int _heap_size;
 
+  // Updating the distances from the source in that order will work in
+  // the original graph (which has to be a DAG)
   Vertex **_dp_order;
 
 public:
@@ -95,11 +92,11 @@ public:
 
   ~MTPGraph();
 
-  // Compute the family of path with minimum total length, set the
+  // Compute the family of paths with minimum total length, set the
   // edge occupied fields accordingly.
   void find_best_paths(scalar_t *lengths);
 
-  // Retrieve the path corresponding to the occupied edges, and save
+  // Retrieve the paths corresponding to the occupied edges, and save
   // the result in the nb_paths and paths fields.
   void retrieve_disjoint_paths();