X-Git-Url: https://fleuret.org/cgi-bin/gitweb/gitweb.cgi?a=blobdiff_plain;f=mtp_graph.cc;h=5371732a03e9c85e3b357f16464e36773535a0b7;hb=6c727bc27f1b594b5f3e5a756a0a01c3cb9b1cec;hp=052de17884763a1a32747e149b0f047e3ee23f20;hpb=e03634d09a9049c7ae4fb426c67ad513cc84185a;p=mtp.git

diff --git a/mtp_graph.cc b/mtp_graph.cc
index 052de17..5371732 100644
--- a/mtp_graph.cc
+++ b/mtp_graph.cc
@@ -24,19 +24,18 @@
 
 #include "mtp_graph.h"
 
-#include <iostream>
 #include <float.h>
-#include <stdlib.h>
 
 using namespace std;
 
 class Edge {
 public:
-  int id, occupied;
+  int occupied;
   scalar_t length, positivized_length;
   Vertex *origin_vertex, *terminal_vertex;
 
-  // These are the links in the origin_vertex leaving edge list
+  // These fields are used for the linked list of a vertex's leaving
+  // edge list. We have to do insertions / deletions.
   Edge *next_leaving_edge, *pred_leaving_edge;
 
   inline void invert();
@@ -44,7 +43,6 @@ public:
 
 class Vertex {
 public:
-  int id;
   Edge *leaving_edges;
   scalar_t distance_from_source;
   Edge *pred_edge_toward_source;
@@ -111,14 +109,9 @@ MTPGraph::MTPGraph(int nb_vertices, int nb_edges,
   _source = &_vertices[source];
   _sink = &_vertices[sink];
 
-  for(int k = 0; k < _nb_vertices; k++) {
-    _vertices[k].id = k;
-  }
-
   for(int e = 0; e < nb_edges; e++) {
     _vertices[vertex_from[e]].add_leaving_edge(_edges + e);
     _edges[e].occupied = 0;
-    _edges[e].id = e;
     _edges[e].origin_vertex = _vertices + vertex_from[e];
     _edges[e].terminal_vertex = _vertices + vertex_to[e];
   }
@@ -141,9 +134,9 @@ MTPGraph::~MTPGraph() {
 void MTPGraph::print(ostream *os) {
   for(int k = 0; k < _nb_edges; k++) {
     Edge *e = _edges + k;
-    (*os) << e->origin_vertex->id
+    (*os) << e->origin_vertex - _vertices
          << " -> "
-         << e->terminal_vertex->id
+         << e->terminal_vertex - _vertices
          << " "
          << e->length;
     if(e->occupied) {
@@ -158,14 +151,14 @@ void MTPGraph::print_dot(ostream *os) {
   (*os) << "        rankdir=\"LR\";" << endl;
   (*os) << "        node [shape=circle,width=0.75,fixedsize=true];" << endl;
   (*os) << "        edge [color=gray,arrowhead=open]" << endl;
-  (*os) << "        " << _source->id << " [peripheries=2];" << endl;
-  (*os) << "        " << _sink->id << " [peripheries=2];" << endl;
+  (*os) << "        " << _source - _vertices << " [peripheries=2];" << endl;
+  (*os) << "        " << _sink - _vertices << " [peripheries=2];" << endl;
   for(int k = 0; k < _nb_edges; k++) {
     Edge *e = _edges + k;
-    // (*os) << "  " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
-    // << ";"
-    // << endl;
-    (*os) << "        " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
+    (*os) << "        "
+          << e->origin_vertex - _vertices
+          << " -> "
+          << e->terminal_vertex - _vertices
           << " [";
     if(e->occupied) {
       (*os) << "style=bold,color=black,";
@@ -190,15 +183,25 @@ void MTPGraph::force_positivized_lengths() {
   scalar_t residual_error = 0.0;
   scalar_t max_error = 0.0;
 #endif
-  for(int n = 0; n < _nb_vertices; n++) {
-    for(Edge *e = _vertices[n].leaving_edges; e; e = e->next_leaving_edge) {
-      if(e->positivized_length < 0) {
+  for(int k = 0; k < _nb_edges; k++) {
+    Edge *e = _edges + k;
+
+    if(e->positivized_length < 0) {
+
 #ifdef VERBOSE
+      if((e->origin_vertex->last_change < 0 && e->terminal_vertex->last_change >= 0) ||
+         (e->origin_vertex->last_change >= 0 && e->terminal_vertex->last_change < 0)) {
+        cout << "Inconsistent non-connexity (this should never happen)." << endl;
+        abort();
+      }
+      if(e->origin_vertex->last_change >= 0 &&
+         e->terminal_vertex->last_change >= 0 &&
+         e->positivized_length < 0) {
         residual_error -= e->positivized_length;
         max_error = max(max_error, - e->positivized_length);
-#endif
-        e->positivized_length = 0.0;
       }
+#endif
+      e->positivized_length = 0.0;
     }
   }
 #ifdef VERBOSE
@@ -220,8 +223,8 @@ int MTPGraph::is_dag() {
   int front_size = _nb_vertices, pred_front_size;
 
   do {
-    // We set the iteration field of all vertex with incoming edges to
-    // the current iteration value
+    // We set the last_change field of all the vertices with incoming
+    // edges to the current iteration value
     for(int f = 0; f < front_size; f++) {
       v = _front[f];
       for(e = v->leaving_edges; e; e = e->next_leaving_edge) {
@@ -232,7 +235,7 @@ int MTPGraph::is_dag() {
     pred_front_size = front_size;
     front_size = 0;
 
-    // We remove all the vertices without incoming edge
+    // We keep all the vertices with incoming nodes
     for(int f = 0; f < pred_front_size; f++) {
       v = _front[f];
       if(v->last_change == iteration) {
@@ -247,7 +250,7 @@ int MTPGraph::is_dag() {
 }
 
 // This method does not change the edge occupation. It only set
-// properly for every vertex the fields distance_from_source and
+// properly, for every vertex, the fields distance_from_source and
 // pred_edge_toward_source.
 
 void MTPGraph::find_shortest_path() {
@@ -361,42 +364,48 @@ void MTPGraph::find_best_paths(scalar_t *lengths) {
   // Put back the graph in its original state (i.e. invert edges which
   // have been inverted in the process)
   for(int k = 0; k < _nb_edges; k++) {
-    Edge *e = _edges + k;
+    e = _edges + k;
     if(e->occupied) { e->invert(); }
   }
 }
 
 int MTPGraph::retrieve_one_path(Edge *e, Path *path) {
   Edge *f, *next = 0;
-  int l = 0;
+  int l = 0, nb_occupied_next;
 
   if(path) {
-    path->nodes[l++] = e->origin_vertex->id;
+    path->nodes[l++] = e->origin_vertex - _vertices;
     path->length = e->length;
   } else l++;
 
   while(e->terminal_vertex != _sink) {
     if(path) {
-      path->nodes[l++] = e->terminal_vertex->id;
+      path->nodes[l++] = e->terminal_vertex - _vertices;
       path->length += e->length;
     } else l++;
-    int nb_choices = 0;
+
+    nb_occupied_next = 0;
     for(f = e->terminal_vertex->leaving_edges; f; f = f->next_leaving_edge) {
-      if(f->occupied) { nb_choices++; next = f; }
-      if(nb_choices == 0) {
-        cerr << "retrieve_one_path: Non-sink end point." << endl;
-        abort();
-      }
-      if(nb_choices > 1) {
-        cerr << "retrieve_one_path: Non node-disjoint paths." << endl;
-        abort();
-      }
+      if(f->occupied) { nb_occupied_next++; next = f; }
+    }
+
+#ifdef DEBUG
+    if(nb_occupied_next == 0) {
+      cerr << "retrieve_one_path: Non-sink end point." << endl;
+      abort();
+    }
+
+    else if(nb_occupied_next > 1) {
+      cerr << "retrieve_one_path: Non node-disjoint paths." << endl;
+      abort();
     }
+#endif
+
     e = next;
   }
 
   if(path) {
-    path->nodes[l++] = e->terminal_vertex->id;
+    path->nodes[l++] = e->terminal_vertex - _vertices;
     path->length += e->length;
   } else l++;
 
@@ -405,6 +414,7 @@ int MTPGraph::retrieve_one_path(Edge *e, Path *path) {
 
 void MTPGraph::retrieve_disjoint_paths() {
   Edge *e;
+  int p, l;
 
   for(int p = 0; p < nb_paths; p++) delete paths[p];
   delete[] paths;
@@ -416,10 +426,10 @@ void MTPGraph::retrieve_disjoint_paths() {
 
   paths = new Path *[nb_paths];
 
-  int p = 0;
+  p = 0;
   for(e = _source->leaving_edges; e; e = e->next_leaving_edge) {
     if(e->occupied) {
-      int l = retrieve_one_path(e, 0);
+      l = retrieve_one_path(e, 0);
       paths[p] = new Path(l);
       retrieve_one_path(e, paths[p]);
       p++;