X-Git-Url: https://fleuret.org/cgi-bin/gitweb/gitweb.cgi?a=blobdiff_plain;f=mtp_graph.h;h=c9105203405e26a5bff5c239fea9b34fcd46ca48;hb=14e3b33cbe1e0d7deb0b4aa697f6c8b5d43e2963;hp=5842671223347d25a924141723be11f63942f2e9;hpb=2b3a2e10ec226f1610b9c39abd20f0899a34a652;p=mtp.git diff --git a/mtp_graph.h b/mtp_graph.h index 5842671..c910520 100644 --- a/mtp_graph.h +++ b/mtp_graph.h @@ -57,8 +57,8 @@ class MTPGraph { void dp_distance_propagation(); // 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 @@ -66,10 +66,9 @@ 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(); + // 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_distances(); int _nb_vertices, _nb_edges; Vertex *_source, *_sink; @@ -77,11 +76,12 @@ class MTPGraph { 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 +95,11 @@ 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();