Introduce Options::contiguous_vertices.

For now only used and checked in find_vertex.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/contiguous_vertices@833 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: ceee8ba85eb21991a836b8f1d1117bcaafeb8c1b

2 files changed, 17 insertions, 2 deletions

diff --git a/src/Simplex_tree/concept/SimplexTreeOptions.h b/src/Simplex_tree/concept/SimplexTreeOptions.h
index a50a2bf1..4a88f936 100644
--- a/src/Simplex_tree/concept/SimplexTreeOptions.h
+++ b/src/Simplex_tree/concept/SimplexTreeOptions.h
@@ -37,5 +37,7 @@ struct SimplexTreeOptions {
   static constexpr bool store_key;
   /// If true, each simplex has extra storage for one `Filtration_value`, and this value is propagated by operations like `Gudhi::Simplex_tree<SimplexTreeOptions>::expansion`. Without it, `Persistent_cohomology` degenerates to computing usual (non-persistent) cohomology.
   static constexpr bool store_filtration;
+  /// If true, the list of vertices present in the complex must always be 0, ..., num_vertices-1, without any hole.
+  static constexpr bool contiguous_vertices;
 };
 
diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h
index 96565ff1..d19071fb 100644
--- a/src/Simplex_tree/include/gudhi/Simplex_tree.h
+++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h
@@ -85,6 +85,7 @@ struct Simplex_tree_options_full_featured {
   typedef int Simplex_key;
   static const bool store_key = true;
   static const bool store_filtration = true;
+  static const bool contiguous_vertices = true;
 };
 
 /**
@@ -564,9 +565,21 @@ class Simplex_tree {
   /** \brief Returns the Simplex_handle corresponding to the 0-simplex
    * representing the vertex with Vertex_handle v. */
   Simplex_handle find_vertex(Vertex_handle v) {
-    return root_.members_.begin() + v;
+    if (Options::contiguous_vertices) {
+      assert(contiguous_vertices());
+      return root_.members_.begin() + v;
+    } else {
+      return root_.members_.find(v);
+    }
+  }
+
+  /** \private \brief Test if the vertices have contiguous numbering: 0, 1, etc.  */
+  bool contiguous_vertices() const {
+    if(root_.members_.empty()) return true;
+    if(root_.members_.front()!=0) return false;
+    if(root_.members_.back()!=root_.members_.size()-1) return false;
+    return true;
   }
-  //{ return root_.members_.find(v); }
 
  private:
   /** \brief Inserts a simplex represented by a vector of vertex.