X-Git-Url: https://fleuret.org/cgi-bin/gitweb/gitweb.cgi?a=blobdiff_plain;f=mtp_graph.cc;h=cc816c95f899a16220fa09ed0ab3f151578d7329;hb=e9fbecf1c13c63a717c1b359c24287dbce23d4ed;hp=95dc4510af14e4cd8888e943209c8f808235d7dd;hpb=79a4a9ab164a667ecb551078e1cd773e2140e3c2;p=mtp.git

diff --git a/mtp_graph.cc b/mtp_graph.cc
index 95dc451..cc816c9 100644
--- a/mtp_graph.cc
+++ b/mtp_graph.cc
@@ -20,6 +20,7 @@
 
 #include <iostream>
 #include <float.h>
+#include <stdlib.h>
 
 using namespace std;
 
@@ -82,37 +83,17 @@ void Vertex::del_edge(Edge *e) {
 
 //////////////////////////////////////////////////////////////////////
 
-void MTPGraph::print() {
-  for(int k = 0; k < _nb_edges; k++) {
-    Edge *e = _edges + k;
-    cout << e->origin_vertex->id
-         << " -> "
-         << e->terminal_vertex->id
-         << " "
-         << e->length;
-    if(e->occupied) {
-      cout << " *";
-    }
-    cout << endl;
-  }
+Path::Path(int l) {
+  length = l;
+  nodes = new int[length];
 }
 
-void MTPGraph::print_dot() {
-  cout << "digraph {" << endl;
-  cout << "  node[shape=circle];" << endl;
-  for(int k = 0; k < _nb_edges; k++) {
-    Edge *e = _edges + k;
-    if(e->occupied) {
-      cout << "  " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
-           << " [style=bold,color=black,label=\"" << -e->length << "\"];" << endl;
-    } else {
-      cout << "  " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
-           << " [color=gray,label=\"" << e->length << "\"];" << endl;
-    }
-  }
-  cout << "}" << endl;
+Path::~Path() {
+  delete[] nodes;
 }
 
+//////////////////////////////////////////////////////////////////////
+
 MTPGraph::MTPGraph(int nb_vertices, int nb_edges,
                    int *from, int *to,
                    int source, int sink) {
@@ -139,6 +120,8 @@ MTPGraph::MTPGraph(int nb_vertices, int nb_edges,
     _edges[e].terminal_vertex = _vertices + to[e];
   }
 
+  paths = 0;
+  nb_paths = 0;
 }
 
 MTPGraph::~MTPGraph() {
@@ -146,8 +129,48 @@ MTPGraph::~MTPGraph() {
   delete[] _edges;
   delete[] _front;
   delete[] _new_front;
+  for(int p = 0; p < nb_paths; p++) delete paths[p];
+  delete[] paths;
+}
+
+//////////////////////////////////////////////////////////////////////
+
+void MTPGraph::print(ostream *os) {
+  for(int k = 0; k < _nb_edges; k++) {
+    Edge *e = _edges + k;
+    (*os) << e->origin_vertex->id
+         << " -> "
+         << e->terminal_vertex->id
+         << " "
+         << e->length;
+    if(e->occupied) {
+      (*os) << " *";
+    }
+    (*os) << endl;
+  }
+}
+
+void MTPGraph::print_dot(ostream *os) {
+  (*os) << "digraph {" << endl;
+  (*os) << "  node[shape=circle];" << endl;
+  for(int k = 0; k < _nb_edges; k++) {
+    Edge *e = _edges + k;
+    // (*os) << "  " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
+          // << ";"
+          // << endl;
+    if(e->occupied) {
+      (*os) << "  " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
+           << " [style=bold,color=black,label=\"" << e->length << "\"];" << endl;
+    } else {
+      (*os) << "  " << e->origin_vertex->id << " -> " << e->terminal_vertex->id
+           << " [color=gray,label=\"" << e->length << "\"];" << endl;
+    }
+  }
+  (*os) << "}" << endl;
 }
 
+//////////////////////////////////////////////////////////////////////
+
 void MTPGraph::initialize_positivized_lengths_with_min() {
   scalar_t length_min = 0;
   for(int n = 0; n < _nb_vertices; n++) {
@@ -165,26 +188,29 @@ void MTPGraph::initialize_positivized_lengths_with_min() {
 void MTPGraph::update_positivized_lengths() {
   for(int k = 0; k < _nb_edges; k++) {
     Edge *e = _edges + k;
-    e->positivized_length += e->terminal_vertex->distance_from_source - e->terminal_vertex->distance_from_source;
+    e->positivized_length +=
+      e->origin_vertex->distance_from_source - e->terminal_vertex->distance_from_source;
   }
 }
 
 void MTPGraph::force_positivized_lengths() {
 #ifdef VERBOSE
   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) {
 #ifdef VERBOSE
         residual_error -= e->positivized_length;
+        max_error = max(max_error, fabs(e->positivized_length));
 #endif
         e->positivized_length = 0.0;
       }
     }
   }
 #ifdef VERBOSE
-  cerr << "residual_error " << residual_error << endl;
+  cerr << "residual_error " << residual_error << " max_error " << residual_error << endl;
 #endif
 }
 
@@ -212,6 +238,32 @@ void MTPGraph::find_shortest_path(Vertex **_front, Vertex **_new_front) {
   do {
     _new_front_size = 0;
     iteration++;
+
+    // for(int k = 0; k < _nb_edges; k++) {
+      // Edge *e = _edges + k;
+      // d = e->origin_vertex->distance_from_source + e->positivized_length;
+      // if(d < e->terminal_vertex->distance_from_source) {
+        // e->terminal_vertex->distance_from_source = d;
+        // _new_front_size++;
+      // }
+    // }
+
+    // for(int n = 0; n < _nb_vertices; n++) {
+      // v = &_vertices[n];
+      // for(e = v->leaving_edges; e; e = e->next_leaving_edge) {
+        // d = v->distance_from_source + e->positivized_length;
+        // tv = e->terminal_vertex;
+        // if(d < tv->distance_from_source) {
+          // tv->distance_from_source = d;
+          // tv->best_pred_edge_to_source = e;
+          // if(tv->iteration < iteration) {
+            // _new_front[_new_front_size++] = tv;
+            // tv->iteration = iteration;
+          // }
+        // }
+      // }
+    // }
+
     for(int f = 0; f < _front_size; f++) {
       v = _front[f];
       for(e = v->leaving_edges; e; e = e->next_leaving_edge) {
@@ -236,18 +288,35 @@ void MTPGraph::find_shortest_path(Vertex **_front, Vertex **_new_front) {
     _new_front_size = _front_size;
     _front_size = tmp_front_size;
   } while(_front_size > 0);
+
+#ifdef DEBUG
+  scalar_t min_delta = 0, delta;
+  for(int k = 0; k < _nb_edges; k++) {
+    Edge *e = _edges + k;
+    // d = e->origin_vertex->distance_from_source + e->positivized_length;
+    // if(d > e->terminal_vertex->distance_from_source) { abort(); }
+    delta = e->positivized_length +
+               (e->origin_vertex->distance_from_source - e->terminal_vertex->distance_from_source);
+    min_delta = min(delta, min_delta);
+  }
+  cout << "min_delta = " << delta << endl;
+#endif
 }
 
-void MTPGraph::find_best_paths(scalar_t *lengths, int *result_edge_occupation) {
+void MTPGraph::find_best_paths(scalar_t *lengths) {
   scalar_t total_length;
   Vertex *v;
   Edge *e;
 
   for(int e = 0; e < _nb_edges; e++) {
     _edges[e].length = lengths[e];
+    _edges[e].occupied = 0;
     _edges[e].positivized_length = _edges[e].length;
   }
 
+  cout << "********************************************************" << endl;
+  // print_dot(&cout);
+
   // We use one iteration of find_shortest_path simply to propagate
   // the distance to make all the edge lengths positive.
   find_shortest_path(_front, _new_front);
@@ -274,7 +343,7 @@ void MTPGraph::find_best_paths(scalar_t *lengths, int *result_edge_occupation) {
       // If that length is negative
       if(total_length < 0.0) {
 #ifdef VERBOSE
-        cout << "Found a path of length " << total_length << endl;
+        cerr << "Found a path of length " << total_length << endl;
 #endif
         // Invert all the edges along the best path
         v = _sink;
@@ -294,6 +363,60 @@ void MTPGraph::find_best_paths(scalar_t *lengths, int *result_edge_occupation) {
   for(int k = 0; k < _nb_edges; k++) {
     Edge *e = _edges + k;
     if(e->occupied) { e->revert(); }
-    result_edge_occupation[k] = e->occupied;
+  }
+}
+
+int MTPGraph::retrieve_one_path(Edge *e, int *nodes) {
+  Edge *f, *next = 0;
+  int l = 0;
+
+  if(nodes) { nodes[l++] = e->origin_vertex->id; }
+  else l++;
+
+  while(e->terminal_vertex != _sink) {
+    if(nodes) { nodes[l++] = e->terminal_vertex->id; }
+    else l++;
+    int nb_choices = 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 << "Non-sink path end point?!" << endl;
+        abort();
+      }
+      if(nb_choices > 1) {
+        cerr << "Non node-disjoint path, can not retrieve." << endl;
+        abort();
+      }
+    }
+    e = next;
+  }
+
+  if(nodes) { nodes[l++] = e->terminal_vertex->id; }
+  else l++;
+
+  return l;
+}
+
+void MTPGraph::retrieve_disjoint_paths() {
+  Edge *e;
+
+  for(int p = 0; p < nb_paths; p++) delete paths[p];
+  delete[] paths;
+
+  nb_paths = 0;
+  for(e = _source->leaving_edges; e; e = e->next_leaving_edge) {
+    if(e->occupied) { nb_paths++; }
+  }
+
+  paths = new Path *[nb_paths];
+
+  int p = 0;
+  for(e = _source->leaving_edges; e; e = e->next_leaving_edge) {
+    if(e->occupied) {
+      int l = retrieve_one_path(e, 0);
+      paths[p] = new Path(l);
+      retrieve_one_path(e, paths[p]->nodes);
+      p++;
+    }
   }
 }