Python/data_structures/AVL/AVL.py

'''
A AVL tree
'''


class Node:

    def __init__(self, label):
        self.label = label
        self.height = 0

    @property
    def right(self):
        return self.right

    @right.setter
    def right(self, node):
        node.parent = self
        self.right = node

    @property
    def left(self):
        return self.left

    @left.setter
    def left(self, node):
        node.parent = self
        self.left = node

    @property
    def parent(self):
        return self.parent

    @parent.setter
    def parent(self, node):
        self.parent = node
        self.height = self.parent.height + 1


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.root.height = 0
            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.label < curr_node.label:
                        curr_node = curr_node.left
                    else:
                        curr_node = curr_node.right
                else:
                    if node.label < dad_node.label:
                        dad_node.left = node
                    else:
                        dad_node.right = node

                    self.rebalance(dad_node)
                    self.size += 1
                    break

    def rebalance(self, node):
        height_right = 0
        height_left = 0
        n = node
        while n is not None:
            height_right = 0
            height_left = 0

            if node.getRight() is not None:
                height_right = node.getRight().getHeight()

            if node.getLeft() is not None:
                height_left = node.getLeft().getHeight()

            if abs(height_left - height_right) > 1:
                if height_left > height_right:
                    # left_child = node.getRight()
                    if ():
                        self.rotate_left(n)
                        break
                    else:
                        self.double_rotate_right(n)
                        break
                else:
                    right_child = node.right
                    if right_child is not None:
                        h_right = (right_child.right.height
                            if (right_child.right is not None) else 0)
                        h_left = (right_child.left.height
                            if (right_child.left is not None) else 0)

                    if (h_left > h_right):
                        self.double_rotate_left(n)
                        break
                    else:
                        self.rotate_right(n)
                        break
            n = n.getParent()

    def rotate_left(self, node):
        pass

    def rotate_right(self, node):
        aux = node.parent
        node.parent = node
        node.left = aux

        print(node.parent.label)
        print(node.parent.right.label)
        print(node.parent.left.label)

    def double_rotate_left(self, node):
        self.rotate_right(node.getRight().getRight())
        self.rotate_left(node)

    def double_rotate_right(self, node):
        self.rotate_left(node.getLeft().getLeft())
        self.rotate_right(node)

    def empty(self):
        if self.root is None:
            return True
        return False

    def preShow(self, curr_node):
        if curr_node is not None:
            self.preShow(curr_node.getLeft())
            print(curr_node.getLabel(), end=" ")
            self.preShow(curr_node.getRight())

    def preorden(self, curr_node):
        if curr_node is not None:
            self.preShow(curr_node.getLeft())
            self.preShow(curr_node.getRight())
            print(curr_node.getLabel(), end=" ")

    def getRoot(self):
        return self.root

t = AVL()
# t.insert(1)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(2)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(3)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# print(t.getRoot().getHeight())
# print(t.getRoot().getRight().getHeight())
t.insert(1)
t.insert(2)
t.insert(3)
# t.insert(4)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(5)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(6)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(7)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(8)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(9)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(10)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(11)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(12)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(13)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(14)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())
# print("\n")
# t.insert(15)
# t.preShow(t.getRoot())
# print("\n")
# t.preorden(t.getRoot())