Prevent inserting some obvious duplicates in the add_entries function.

git-svn-id: https://svn.dealii.org/trunk@18564 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/lac/source/compressed_simple_sparsity_pattern.cc b/deal.II/lac/source/compressed_simple_sparsity_pattern.cc
index c3ae666ded0bb895c35693e7893270dd62b8bf8e..e7a8ba9eb7f63f3c26c0b00a2828e67e31664ee6 100644 (file)
--- a/deal.II/lac/source/compressed_simple_sparsity_pattern.cc
+++ b/deal.II/lac/source/compressed_simple_sparsity_pattern.cc
@@ -35,8 +35,7 @@ CompressedSimpleSparsityPattern::Line::add_entries (ForwardIterator begin,
   if (n_elements <= 0)
     return;
 
-  const unsigned int n_cols = static_cast<unsigned int>(n_elements);
-  const unsigned int stop_size = entries.size() + n_cols;
+  const unsigned int stop_size = entries.size() + n_elements;
 
   if (indices_are_sorted == true && n_elements > 3)
     {
@@ -47,7 +46,11 @@ CompressedSimpleSparsityPattern::Line::add_entries (ForwardIterator begin,
        ForwardIterator test = begin, test1 = begin;
        ++test1;
        for ( ; test1 != end; ++test, ++test1)
+         {
+           if (*test1 <= *test)
+             std::cout << end-begin << " " << test1-begin << " " << *test1 << " " << *test << "  " << std::flush;
          Assert (*test1 > *test, ExcInternalError());
+         }
       }
 #endif
 
@@ -57,18 +60,49 @@ CompressedSimpleSparsityPattern::Line::add_entries (ForwardIterator begin,
          return;
        }
 
-                                  // resize vector by just inserting the
-                                  // list
-      const unsigned int col = *begin;
+                                  // find a possible insertion point for
+                                  // the first entry. check whether the
+                                  // first entry is a duplicate before
+                                  // actually doing something.
+      ForwardIterator my_it = begin;
+      unsigned int col = *my_it;
       std::vector<unsigned int>::iterator it = 
        std::lower_bound(entries.begin(), entries.end(), col);
+      while (*it == col) 
+       {
+         ++my_it;
+         if (my_it == end)
+           break;
+         col = *my_it;
+                                  // check the very next entry in the
+                                  // current array
+         ++it;
+         if (it == entries.end())
+           break;
+         if (*it > col)
+           break;
+         if (*it == col)
+           continue;
+                                  // ok, it wasn't the very next one, do a
+                                  // binary search to find the insert point
+         it = std::lower_bound(it, entries.end(), col);
+         if (it == entries.end())
+           break;
+       }
+                                  // all input entries were duplicates.
+      if (my_it == end)
+       return;
+
+                                  // resize vector by just inserting the
+                                  // list
       const unsigned int pos1 = it - entries.begin();
-      entries.insert (it, begin, end);
+      Assert (pos1 <= entries.size(), ExcInternalError());
+      entries.insert (it, my_it, end);
       it = entries.begin() + pos1;
+      Assert (entries.size() >= (unsigned int)(it-entries.begin()), ExcInternalError());
 
                                   // now merge the two lists.
-      ForwardIterator my_it = begin;
-      std::vector<unsigned int>::iterator it2 = it + n_cols;
+      std::vector<unsigned int>::iterator it2 = it + (end-my_it);
 
                                   // as long as there are indices both in
                                   // the end of the entries list and in the