def _left_rotate(node):
'''
FIXME:
Implement this function.
The lecture videos provide a high-level overview of tree
rotations,
and the textbook provides full python code.
The textbook's class hierarchy for their AVL tree code is
fairly different from our class hierarchy,
however, so you will have to adapt their code.
'''
if node is None or node.right is None:
return node
new = Node(node.right.value)
new.right = node.right.right
leftnode = Node(node.value)
leftnode.left = node.left
leftnode.right = node.right.left
new.left = leftnode
return new
def _remove(node, value):
if node is None:
return
if value > node.value and node.right:
node.right = BST._remove(node.right, value)
return node
elif value < node.value and node.left:
node.left = BST._remove(node.left, value)
return node
elif value == node.value:
if node.left is None and node.right is None:
return None
elif node.left is None:
return node.right
elif node.right is None:
return node.left
else:
smallest = BST._find_smallest(node.right)
if smallest == node.right.value:
ret = node.right
ret.left = node.left
else:
ret = Node(smallest)
ret.left = node.left
ret.right = BST._remove(node.right, smallest)
return ret
else:
return node
def _right_rotate(node):
'''
FIXME:
Implement this function.
The lecture videos provide a high-level overview of tree rotations,
and the textbook provides full python code.
however, so you will have to adapt their code.
'''
left = Node(node.left.value)
left.left = node.left.left
nr = Node(node.value)
nr.right = node.right
nr.left = node.left.right
left.right = nr
return left
def _right_rotate(node):
if node is None or node.left is None:
return node
new_root = Node(node.left.value)
new_root.left = node.left.left
new_root.right = Node(node.value)
new_root.right.right = node.right
if node.left.right:
new_root.right.left = node.left.right
return new_root
def _left_rotate(node):
if node is None or node.right is None:
return node
new = Node(node.right.value)
new.right = node.right.right
new.left = Node(node.value)
new.left.left = node.left
if node.right.left:
new.left.right = node.right.left
return new
def _right_rotate(node):
'''
FIXME:
Implement this function.
The lecture videos provide a high-level overview of tree rotations,
and the textbook provides full python code.
'''
if node is None or node.left is None:
return node
noda = Node(node.left.value)
noda.left = node.left.left
node_right = Node(node.value)
node_right.right = node.right
node_right.left = node.left.right
noda.right = node_right
return noda
def _right_rotate(node):
'''
FIXME:
Implement this function.
The lecture videos provide a high-level overview of tree rotations,
and the textbook provides full python code.
The textbook's class hierarchy for their AVL tree code
is fairly different from our class hierarchy,
however, so you will have to adapt their code.
'''
if node.left:
old_root = Node(node.value)
old_root.right = node.right
old_root.left = node.left.right
new_root = Node(node.left.value)
new_root.left = node.left.left
new_root.right = old_root
else:
new_root = node
return new_root
def _insert(root: Node, number: int):
if root is None:
root = Node(number)
return root
else:
if root.value == number:
return root
elif number < root.value:
root.left = BST._insert(root.left, number)
else:
root.right = BST._insert(root.right, number)
return root
def _left_rotate(node):
'''
FIXME:
Implement this function.
The lecture videos provide a high-level overview of tree rotations,
and the textbook provides full python code.
The textbook's class hierarchy for their AVL tree code is fairly different from our class hierarchy,
however, so you will have to adapt their code.
'''
assert(node.right is not None)
root = Node(node.right.value)
root.right = node.right.right
root.left = Node(node.value)
root.left.left = node.left
root.left.right = node.right.left
return root
def _right_rotate(node):
'''
FIXME:
Implement this function.
The lecture videos provide a high-level overview of tree rotations,
and the textbook provides full python code.
The textbook's class hierarchy for their AVL tree code is fairly
different from our class hierarchy,
however, so you will have to adapt their code.
'''
swap = AVLTree._copy_nodes(node.left.right)
newnode = Node(node.left.value)
newnode.left = AVLTree._copy_nodes(node.left.left)
newnode.right = AVLTree._copy_nodes(node)
newnode.right.left = swap
return newnode
