RBTree seems generally OK now

git-svn-id: https://bucket.mit.edu/svn/nilm/nilmdb@11379 ddd99763-3ecb-0310-9145-efcb8ce7c51f

nilmdb/rbtree.py

@@ -187,7 +187,7 @@ class RBTree(object):
             # y is the node to splice out, x is its child
             y.left = z.left
             y.right = z.right
-            z.parent = z.parent
+            y.parent = z.parent
             z.left.parent = y
             z.right.parent = y
             if z is z.parent.left:

tests/test_rbtree.py

@@ -26,23 +26,44 @@ class TestRBTree:
     def test_rbtree_big(self):
         import random
         random.seed(1234)
-        # make a set of 500 intervals
+
+        # make a set of 500 intervals, inserted in order
+        rb = RBTree()
+        j = 500
+        for i in xrange(j):
+            rb.insert(RBNode(None, i, i+1))
+
+        # show the graph
+        rb.render_dot_live("in-order insert")
+
+        # remove about half of them
+        for i in random.sample(xrange(j),j):
+            if random.randint(0,1):
+                rb.delete(rb.find(i, i+1))
+
+        # show the graph
+        rb.render_dot_live("in-order insert, random delete")
+
+        # make a set of 500 intervals, inserted at random
         rb = RBTree()
         j = 500
         for i in random.sample(xrange(j),j):
-            print "inserting", i
             rb.insert(RBNode(None, i, i+1))
 
         # show the graph
-        rb.render_dot_live("after insert")
+        rb.render_dot_live("random insert")
 
         # remove about half of them
         for i in random.sample(xrange(j),j):
             if random.randint(0,1):
-                print "deleting", i
-                if i == 300:
-                    rb.render_dot_live("before deleting 300")
                 rb.delete(rb.find(i, i+1))
 
         # show the graph
-        rb.render_dot_live("after delete")
+        rb.render_dot_live("random insert, random delete")
+
+        # in-order insert of 250 more
+        for i in xrange(250):
+            rb.insert(RBNode(None, i+500, i+501))
+
+        # show the graph
+        rb.render_dot_live("random insert, random delete, in-order insert")