From abbaf6b4b4b8d10ee8e9054a3b8d262a2f242920 Mon Sep 17 00:00:00 2001
From: Francois Fleuret <francois@fleuret.org>
Date: Wed, 29 Aug 2012 17:07:13 +0200
Subject: [PATCH] Cosmetics + added a full check in find_shortest_path when
 compiling in DEBUG.

---
 mtp_graph.cc | 43 +++++++++++++++++++++----------------------
 1 file changed, 21 insertions(+), 22 deletions(-)

diff --git a/mtp_graph.cc b/mtp_graph.cc
index 7781fc1..d3b921b 100644
--- a/mtp_graph.cc
+++ b/mtp_graph.cc
@@ -205,7 +205,7 @@ void MTPGraph::force_positivized_lengths() {
 }
 
 int MTPGraph::is_dag() {
-  Vertex *v, *tv;
+  Vertex *v;
   Edge *e;
 
   // We put everybody in the front
@@ -214,35 +214,31 @@ int MTPGraph::is_dag() {
     _front[k] = &_vertices[k];
   }
 
-  int front_size = _nb_vertices, nb_with_incoming;
   int iteration = 0;
-  int new_front_size, pred_front_size;
+  int front_size = _nb_vertices, pred_front_size;
 
   do {
     iteration++;
-    nb_with_incoming = 0;
 
     // We set the iteration field of all vertex 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) {
-        tv = e->terminal_vertex;
-        tv->iteration = iteration;
+        e->terminal_vertex->iteration = iteration;
       }
     }
 
-    new_front_size = 0;
+    pred_front_size = front_size;
+    front_size = 0;
+
     // We remove all the vertices without incoming edge
-    for(int f = 0; f < front_size; f++) {
+    for(int f = 0; f < pred_front_size; f++) {
       v = _front[f];
       if(v->iteration == iteration) {
-        _front[new_front_size++] = v;
+        _front[front_size++] = v;
       }
     }
-
-    pred_front_size = front_size;
-    front_size = new_front_size;
   } while(front_size < pred_front_size);
 
   return front_size == 0;
@@ -254,11 +250,21 @@ int MTPGraph::is_dag() {
 
 void MTPGraph::find_shortest_path() {
   Vertex **tmp_front;
-  int tmp_front_size;
   Vertex *v, *tv;
   Edge *e;
   scalar_t d;
 
+#ifdef DEBUG
+  if(is_dag()) {
+    cout << "find_shortest_path: DAG -> ok" << endl;
+  } else {
+    for(int e = 0; e < _nb_edges; e++) {
+      if(_edges[e].positivized_length < 0)  abort();
+    }
+    cout << "find_shortest_path: All positivized_length are positive -> ok" << endl;
+  }
+#endif
+
   for(int k = 0; k < _nb_vertices; k++) {
     _vertices[k].distance_from_source = FLT_MAX;
     _vertices[k].pred_edge_toward_source = 0;
@@ -291,13 +297,9 @@ void MTPGraph::find_shortest_path() {
       }
     }
 
-    tmp_front = _new_front;
-    _new_front = _front;
-    _front = tmp_front;
+    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;
+    front_size = new_front_size;
   } while(front_size > 0);
 }
 
@@ -312,9 +314,6 @@ void MTPGraph::find_best_paths(scalar_t *lengths) {
     _edges[e].positivized_length = _edges[e].length;
   }
 
-  // Let's be a bit paranoid
-  ASSERT(is_dag());
-
   // We call find_shortest_path here to set properly the distances to
   // the source, so that we can make all the edge lengths positive at
   // the first iteration.
-- 
2.20.1