2017-07-04 16:48:27 +00:00
|
|
|
'''
|
|
|
|
A AVL tree
|
|
|
|
'''
|
|
|
|
|
|
|
|
|
|
|
|
class Node:
|
|
|
|
|
|
|
|
def __init__(self, label):
|
|
|
|
self.label = label
|
|
|
|
self.left = None
|
|
|
|
self.rigt = None
|
|
|
|
self.parent = None
|
|
|
|
self.height = 0
|
|
|
|
|
|
|
|
def getLabel(self):
|
|
|
|
return self.label
|
|
|
|
|
|
|
|
def setLabel(self, label):
|
|
|
|
self.label = label
|
|
|
|
|
|
|
|
def getLeft(self):
|
|
|
|
return self.left
|
|
|
|
|
|
|
|
def setLeft(self, left):
|
|
|
|
self.left = left
|
|
|
|
|
|
|
|
def getRight(self):
|
|
|
|
return self.rigt
|
|
|
|
|
|
|
|
def setRight(self, right):
|
|
|
|
self.rigt = right
|
|
|
|
|
|
|
|
def getParent(self):
|
|
|
|
return self.parent
|
|
|
|
|
|
|
|
def setParent(self, parent):
|
|
|
|
self.parent = parent
|
|
|
|
|
|
|
|
def setHeight(self, height):
|
|
|
|
self.height = height
|
|
|
|
|
|
|
|
def getHeight(self, height):
|
|
|
|
return self.height
|
|
|
|
|
|
|
|
|
|
|
|
class AVL:
|
|
|
|
|
|
|
|
def __init__(self):
|
|
|
|
self.root = None
|
|
|
|
self.size = 0
|
|
|
|
|
|
|
|
def insert(self, value):
|
|
|
|
node = Node(value)
|
|
|
|
if self.root is None:
|
|
|
|
self.root = node
|
|
|
|
self.size = 1
|
|
|
|
else:
|
|
|
|
# Same as Binary Tree
|
|
|
|
dad_node = None
|
|
|
|
curr_node = self.root
|
|
|
|
|
|
|
|
while True:
|
|
|
|
if curr_node is not None:
|
|
|
|
|
|
|
|
dad_node = curr_node
|
|
|
|
|
|
|
|
if node.getLabel() < curr_node.getLabel():
|
|
|
|
curr_node = curr_node.getLeft()
|
|
|
|
else:
|
|
|
|
curr_node = curr_node.getRight()
|
|
|
|
else:
|
|
|
|
if node.getLabel() < dad_node.getLabel():
|
|
|
|
dad_node.setLeft(node)
|
|
|
|
dad_node.setHeight(dad_node.getHeight() + 1)
|
|
|
|
|
|
|
|
if (dad_node.getRight().getHeight() -
|
|
|
|
dad_node.getLeft.getHeight() > 1):
|
|
|
|
self.rebalance(dad_node)
|
|
|
|
|
|
|
|
else:
|
|
|
|
dad_node.setRight(node)
|
|
|
|
dad_node.setHeight(dad_node.getHeight() + 1)
|
|
|
|
|
|
|
|
if (dad_node.getRight().getHeight() -
|
|
|
|
dad_node.getLeft.getHeight() > 1):
|
|
|
|
self.rebalance(dad_node)
|
|
|
|
break
|
|
|
|
|
|
|
|
def rebalance(self, node):
|
2017-07-05 18:37:47 +00:00
|
|
|
if (node.getRight().getHeight() -
|
|
|
|
node.getLeft.getHeight() > 1):
|
|
|
|
if (node.getRight().getHeight() >
|
|
|
|
node.getLeft.getHeight()):
|
|
|
|
pass
|
|
|
|
else:
|
|
|
|
pass
|
|
|
|
pass
|
|
|
|
elif (node.getRight().getHeight() -
|
|
|
|
node.getLeft.getHeight() > 2):
|
|
|
|
if (node.getRight().getHeight() >
|
|
|
|
node.getLeft.getHeight()):
|
|
|
|
pass
|
|
|
|
else:
|
|
|
|
pass
|
|
|
|
pass
|
2017-07-04 16:48:27 +00:00
|
|
|
pass
|
|
|
|
|
|
|
|
def rotate_left(self, node):
|
2017-07-05 18:37:47 +00:00
|
|
|
# TODO: is this pythonic enought?
|
|
|
|
aux = node.getLabel()
|
|
|
|
node = aux.getRight()
|
|
|
|
node.setHeight(node.getHeight() - 1)
|
|
|
|
node.setLeft(Node(aux))
|
|
|
|
node.getLeft().setHeight(node.getHeight() + 1)
|
|
|
|
node.getRight().setHeight(node.getRight().getHeight() - 1)
|
2017-07-04 16:48:27 +00:00
|
|
|
|
|
|
|
def rotate_right(self, node):
|
2017-07-05 18:37:47 +00:00
|
|
|
aux = node.getLabel()
|
|
|
|
node = aux.getLeft()
|
|
|
|
node.setHeight(node.getHeight() - 1)
|
|
|
|
node.setRight(Node(aux))
|
|
|
|
node.getLeft().setHeight(node.getHeight() + 1)
|
|
|
|
node.getLeft().setHeight(node.getLeft().getHeight() - 1)
|
2017-07-04 16:48:27 +00:00
|
|
|
|
|
|
|
def double_rotate_left(self, node):
|
2017-07-06 19:13:56 +00:00
|
|
|
self.rotate_right(node.getRight().getRight())
|
|
|
|
self.rotate_left(node)
|
2017-07-04 16:48:27 +00:00
|
|
|
|
2017-07-06 19:13:56 +00:00
|
|
|
def double_rotate_right(self, node):
|
|
|
|
self.rotate_left(node.getLeft().getLeft())
|
|
|
|
self.rotate_right(node)
|