--- nfo/python/scripts/sixdegrees/sixdegrees.py	2008/02/06 01:45:22	1.2
+++ nfo/python/scripts/sixdegrees/sixdegrees.py	2008/02/06 22:58:00	1.3
@@ -1,4 +1,4 @@
-# $Id: sixdegrees.py,v 1.2 2008/02/06 01:45:22 joko Exp $
+# $Id: sixdegrees.py,v 1.3 2008/02/06 22:58:00 joko Exp $
 
 # (c) 2008 Andreas Motl <andreas.motl@ilo.de>
 
@@ -15,18 +15,24 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from sets import Set
+#from sets import Set
 
 class Node:
   
   def __init__(self, id):
     self.id = id
-    self.children = Set()
+    self.children = []
   
   def addChild(self, child):
-    self.children.add(child)
+    # with Set
+    #self.children.add(child)
+    
+    # with list
+    if not child in self.children:
+      self.children.append(child)
 
   def __repr__(self):
+    #print "repr-node"
     children_ids = []
     for child in self.children:
       child_id = str(child.id)
@@ -73,6 +79,10 @@
   # extended "Depth Limited search (DLS)" implementation
   # see http://en.wikipedia.org/wiki/Depth-limited_search
   def DLS(self, node, goal, current_depth, max_depth, result, path=[]):
+    
+    # break recursion if node already visited to prevent looping
+    if node in path: return
+    
     path.append(node)
     #print "checking node %s on level %s" % (node, current_depth)
     #print "path:", path
@@ -84,8 +94,6 @@
         mynode = stack.pop()
         if current_depth < max_depth:
           self.DLS(mynode, goal, current_depth + 1, max_depth, result, path)
-        else:
-          pass
     path.pop()
 
   def DLS_orig(self, node, goal, current_depth, max_depth):
@@ -102,6 +110,7 @@
           pass
 
   def __repr__(self):
+    #print "repr-graph"
     payload = ''
     for key, node in self.index.iteritems():
       payload += str(node) + "\n"