X-Git-Url: https://www.fleuret.org/cgi-bin/gitweb/gitweb.cgi?a=blobdiff_plain;f=mtp.cc;h=118e521678e05f415b80173cf421f3830b0a38a2;hb=0f54e5005de0f05d4bc400f23181301eb40f469e;hp=8f37fd6f624f526a8e8dc1172320b9b004391b45;hpb=ad2517dfc2d6dd190cfe865c6ac87ff6e3a4bc05;p=mtp.git

diff --git a/mtp.cc b/mtp.cc
index 8f37fd6..118e521 100644
--- a/mtp.cc
+++ b/mtp.cc
@@ -33,254 +33,16 @@
 
 using namespace std;
 
-typedef float scalar_t;
+#include "mtp_graph.h"
 
-#ifdef DEBUG
-#define ASSERT(x) if(!(x)) { \
-  std::cerr << "ASSERT FAILED IN " << __FILE__ << ":" << __LINE__ << endl; \
-  abort(); \
-}
-#else
-#define ASSERT(x)
-#endif
-
-class Vertex;
-
-class Edge {
-public:
-  int id, occupied;
-  scalar_t length, work_length;
-  Vertex *terminal_vertex;
-  Edge *next, *pred;
-};
-
-class Vertex {
-public:
-  int id, iteration;
-  Edge *root_edge;
-  scalar_t distance_from_source;
-  Vertex *pred_vertex;
-  Edge *pred_edge;
-
-  Vertex() { root_edge = 0; }
-
-  inline void add_edge(Edge *e) {
-    e->next = root_edge;
-    e->pred = 0;
-    if(root_edge) { root_edge->pred = e; }
-    root_edge = e;
-  }
-
-  inline void del_edge(Edge *e) {
-    if(e == root_edge) { root_edge = e->next; }
-    if(e->pred) { e->pred->next = e->next; }
-    if(e->next) { e->next->pred = e->pred; }
-  }
-};
-
-class Graph {
-  void initialize_work_lengths();
-  void update_work_length();
-  void find_shortest_path(Vertex **front, Vertex **new_front);
-
-  int nb_vertices;
-  Edge *edge_heap;
-  Vertex *vertices;
-  Vertex *source, *sink;
-public:
-  Graph(int nb_vertices, int nb_edges, int *from, int *to, scalar_t *lengths,
-        int source, int sink);
-
-  ~Graph();
-
-  void find_best_paths(int *result_edge_occupation);
-  void print();
-};
-
-void Graph::print() {
-  for(int n = 0; n < nb_vertices; n++) {
-    for(Edge *e = vertices[n].root_edge; e; e = e->next) {
-      cout << n << " -> " << e->terminal_vertex->id << " " << e->length;
-      if(e->occupied) {
-        cout << " *";
-      }
-      cout << endl;
-    }
-  }
-}
-
-Graph::Graph(int nb_vrt, int nb_edges,
-             int *from, int *to, scalar_t *lengths,
-             int src, int snk) {
-  nb_vertices = nb_vrt;
-
-  edge_heap = new Edge[nb_edges];
-  vertices = new Vertex[nb_vertices];
-
-  source = &vertices[src];
-  sink = &vertices[snk];
-
-  for(int v = 0; v < nb_vertices; v++) {
-    vertices[v].id = v;
-  }
-
-  for(int e = 0; e < nb_edges; e++) {
-    vertices[from[e]].add_edge(&edge_heap[e]);
-    edge_heap[e].occupied = 0;
-    edge_heap[e].id = e;
-    edge_heap[e].length = lengths[e];
-    edge_heap[e].terminal_vertex = &vertices[to[e]];
-  }
-}
-
-Graph::~Graph() {
-  delete[] vertices;
-  delete[] edge_heap;
-}
-
-void Graph::initialize_work_lengths() {
-  scalar_t length_min = 0;
-  for(int n = 0; n < nb_vertices; n++) {
-    for(Edge *e = vertices[n].root_edge; e; e = e->next) {
-      length_min = min(e->length, length_min);
-    }
-  }
-  for(int n = 0; n < nb_vertices; n++) {
-    for(Edge *e = vertices[n].root_edge; e; e = e->next) {
-      e->work_length = e->length - length_min;
-    }
-  }
-}
-
-void Graph::update_work_length() {
-  for(int n = 0; n < nb_vertices; n++) {
-    scalar_t d = vertices[n].distance_from_source;
-    for(Edge *e = vertices[n].root_edge; e; e = e->next) {
-      e->work_length += d - e->terminal_vertex->distance_from_source;
-    }
-  }
-}
-
-void Graph::find_shortest_path(Vertex **front, Vertex **new_front) {
-  Vertex **tmp_front;
-  int tmp_front_size;
-  Vertex *v, *tv;
-  scalar_t d;
-
-#ifdef VERBOSE
-  scalar_t residual_error = 0.0;
-#endif
-  for(int n = 0; n < nb_vertices; n++) {
-    for(Edge *e = vertices[n].root_edge; e; e = e->next) {
-      if(e->work_length < 0) {
-#ifdef VERBOSE
-        residual_error -= e->work_length;
-#endif
-        e->work_length = 0.0;
-      }
-    }
-  }
-#ifdef VERBOSE
-  cerr << "residual_error " << residual_error << endl;
-#endif
-
-  for(int v = 0; v < nb_vertices; v++) {
-    vertices[v].distance_from_source = FLT_MAX;
-    vertices[v].pred_vertex = 0;
-    vertices[v].pred_edge = 0;
-    vertices[v].iteration = 0;
-  }
-
-  int iteration = 0;
-
-  int front_size = 0, new_front_size;
-  front[front_size++] = source;
-  source->distance_from_source = 0;
-
-  do {
-    new_front_size = 0;
-    iteration++;
-    for(int f = 0; f < front_size; f++) {
-      v = front[f];
-      for(Edge *e = v->root_edge; e; e = e->next) {
-        d = v->distance_from_source + e->work_length;
-        tv = e->terminal_vertex;
-        if(d < tv->distance_from_source) {
-          tv->distance_from_source = d;
-          tv->pred_vertex = v;
-          tv->pred_edge = e;
-          if(tv->iteration < iteration) {
-            new_front[new_front_size++] = tv;
-            tv->iteration = iteration;
-          }
-        }
-      }
-    }
-
-    tmp_front = new_front;
-    new_front = front;
-    front = tmp_front;
-
-    tmp_front_size = new_front_size;
-    new_front_size = front_size;
-    front_size = tmp_front_size;
-  } while(front_size > 0);
-}
-
-void Graph::find_best_paths(int *result_edge_occupation) {
-  Vertex **front = new Vertex *[nb_vertices];
-  Vertex **new_front = new Vertex *[nb_vertices];
-
-  scalar_t total_length;
-
-  initialize_work_lengths();
-
-  do {
-    total_length = 0.0;
-    find_shortest_path(front, new_front);
-    update_work_length();
-
-    // Do we reach the sink?
-    if(sink->pred_edge) {
-
-      // If yes, compute the length of the best path
-      for(Vertex *v = sink; v->pred_edge; v = v->pred_vertex) {
-        total_length += v->pred_edge->length;
-      }
-
-      // If that length is negative
-      if(total_length < 0.0) {
-        // Invert all the edges along the best path
-        for(Vertex *v = sink; v->pred_edge; v = v->pred_vertex) {
-          Edge *e = v->pred_edge;
-          e->terminal_vertex = v->pred_vertex;
-          e->occupied = 1 - e->occupied;
-          e->length = - e->length;
-          e->work_length = - e->work_length;
-          v->pred_vertex->del_edge(e);
-          v->add_edge(e);
-        }
-      }
-    }
-  } while(total_length < 0.0);
-
-  delete[] front;
-  delete[] new_front;
-
-  for(int n = 0; n < nb_vertices; n++) {
-    Vertex *v = &vertices[n];
-    for(Edge *e = v->root_edge; e; e = e->next) {
-      result_edge_occupation[e->id] = e->occupied;
-    }
-  }
-}
+//////////////////////////////////////////////////////////////////////
 
 void find_best_paths(int nb_vertices,
                      int nb_edges, int *ea, int *eb, scalar_t *el,
                      int source, int sink,
                      int *result_edge_occupation) {
-  Graph graph(nb_vertices, nb_edges, ea, eb, el, source, sink);
-  graph.find_best_paths(result_edge_occupation);
+  MTPGraph graph(nb_vertices, nb_edges, ea, eb, source, sink);
+  graph.find_best_paths(el, result_edge_occupation);
 }
 
 void dot_print(int nb_vertices,