class Splay_Tree__Test_Inorder_Traversal_with_Stack_on_10_Node_Tree(
unittest.TestCase):
def setUp(self):
self._splaytree = SplayTree()
self._splaytree.insert(key=5, obj=5)
self._splaytree.insert(key=8, obj=8)
self._splaytree.insert(key=7, obj=7)
self._splaytree.insert(key=9, obj=9)
self._splaytree.insert(key=10, obj=10)
self._splaytree.insert(key=2, obj=2)
self._splaytree.insert(key=1, obj=1)
self._splaytree.insert(key=3, obj=3)
self._splaytree.insert(key=4, obj=4)
self._splaytree.insert(key=6, obj=6)
def test_inorder_traversal_with_10_node_tree(self):
in_order_elements = []
for key, element in self._splaytree.inorder_traversal_with_stack():
in_order_elements.append(element)
self.assertEqual(
10, len(in_order_elements),
'In order traversal on 10 node tree must yield 10 elements')
self.assertEqual(
in_order_elements, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
'In order traversal did not yield expected elements in order')
def tearDown(self):
self._splaytree = None
class Splay_Tree__Test_Inorder_Traversal_Using_Stack_with_empty_Tree(
unittest.TestCase):
def setUp(self):
self._splaytree = SplayTree()
def test_inorder_traversal_with_empty_tree(self):
in_order_elements = []
for key, element in self._splaytree.inorder_traversal_with_stack():
in_order_elements.append(element)
self.assertEqual(
0, len(in_order_elements),
'In order traversal on empty tree must yield no elements')
def tearDown(self):
self._splaytree = None
class SplayedHashBucket(collections.MutableMapping):
'''
A hash bucket is used to hold objects that hash to the same value in a hash table.
This is hash bucket using a splay tree. This masquerades as a python dict in code
where it is used. Since splat tree is used lookups on avg take Olog(n)
Note: HASHBUCKET ITERATION YIELDS KEYS. not the key value pairs in the bucket.
'''
def __init__(self):
self._st = SplayTree()
def __len__(self):
return self._st.node_count
def get(self, key, default = None):
'''
Get object associated with a key and on key miss return specified default. This is
there in Python dict and this class masquerades as dict, we implement it.
'''
try:
value = self[key]
return value
except KeyError:
return default
def __getitem__(self, key):
value = self._st.find(key)
if value == None:
raise KeyError('Key Error: %s ' % repr(key))
return value
def __delitem__(self, key):
if key in self._st:
self._st.remove(key)
else:
raise KeyError('Key Error: %s ' % repr(key))
def __setitem__(self, key, obj):
if key in self._st:
self._st.replace(key, obj)
else:
self._st.insert(key, obj)
def __iter__(self):
for key, value in self._st.inorder_traversal_with_stack():
yield key
class Splay_Tree__Test_Inorder_Traversal_with_Stack_On_Single_Node_Tree(
unittest.TestCase):
def setUp(self):
self._splaytree = SplayTree()
self._splaytree.insert(key=10, obj=10)
def test_inorder_traversal_with_single_node_tree(self):
in_order_elements = []
for key, element in self._splaytree.inorder_traversal_with_stack():
in_order_elements.append(element)
self.assertEqual(
1, len(in_order_elements),
'In order traversal on single node tree must yield one elements')
self.assertEqual(
in_order_elements, [10],
'In order traversal did not yield expected elements in order')
def tearDown(self):
self._splaytree = None
