# HG changeset patch
# User Nathann Cohen <nathann.cohen@gmail.com>
# Date 1262773421 3600
# Node ID 6f5e73ba7b1e4b086a0ef5f988ea3d8cb4993819
# Parent 2ae275b5409c88f93dc342d15ef5a88f3b08c07b
Bug in Graph.block_and_cut_vertices
diff r 2ae275b5409c r 6f5e73ba7b1e sage/graphs/generic_graph.py
a

b


2937  2937  sage: Graph(0).blocks_and_cut_vertices() 
2938  2938  ([], []) 
2939  2939  sage: Graph(1).blocks_and_cut_vertices() 
2940   ([0], [0]) 
 2940  ([0], []) 
2941  2941  sage: Graph(2).blocks_and_cut_vertices() 
2942  2942  Traceback (most recent call last): 
2943  2943  ... 
… 
… 

2961  2961  s = self.vertex_iterator().next() # source 
2962  2962  
2963  2963  if len(self) == 1: # only one vertex 
2964   return [s],[s] 
 2964  return [s],[] 
2965  2965  
2966  2966  if not self.is_connected(): 
2967  2967  raise NotImplementedError("Blocks and cut vertices is currently only implemented for connected graphs.") 