So I have a Binary Search Tree and I am trying to get the height of said tree. I have a self.height attribute that increments whenever I do insert_element(self, value), and decrements when remove_element(self, value) happens. However, I notice that this increments and decrements every time when one of the methods occur and doesn't take into account if node was in the same height which wouldn't change the height.
class Binary_Search_Tree:
class __BST_Node:
def __init__(self, value):
self.value = value
self.lchild = None
self.rchild = None
def __init__(self):
self.__root = None
self.height = 0
def insert_element(self, value):
self._insert(self.__root, value)
def _insert(self, root, value):
node = Binary_Search_Tree.__BST_Node(value)
if root == value:
raise ValueError("Value already exists")
if self.__root is None:
self.__root = Binary_Search_Tree.__BST_Node(value)
self.height += 1
return self.__root
else:
if root.value > node.value:
if root.lchild is None:
root.lchild = node
self.height += 1
return root.lchild
else:
self._insert(root.lchild, value)
elif root.value < node.value:
if root.rchild is None:
root.rchild = node
self.height += 1
return root.rchild
else:
self._insert(root.rchild, value)
return root
def remove_element(self, value):
self.__root = self._remove(self.__root, value)
self.height -= 1
return self.__root
def _remove(self, root, value):
if self.__root is None:
raise ValueError("Tree is empty")
if root.value != value:
raise ValueError("No such value")
if root.value == value:
if root.lchild is None and root.rchild is None:
root = None
self.height -= 1
return root
elif root.lchild is None or root.rchild is None:
if root.lchild is None:
self.height -= 1
return root.rchild
if root.rchild is None:
self.height -= 1
return root.lchild
elif root.lchild and root.rchild:
parent = root
successor = root.rchild
while successor.lchild:
parent = successor
successor = successor.lchild
root.value = successor.value
if parent.lchild == successor:
parent.lchild = successor.rchild
self.height -= 1
return parent.lchild
else:
parent.rchild = successor.rchild
self.height -= 1
return parent.rchild
else:
if root.value > value:
if root.lchild:
root.lchild = self._remove(root.lchild, value)
elif root.value < value:
if root.rchild:
root.rchild = self._remove(root.rchild, value)
return root
def in_order(self):
if self.__root is not None:
self._in(self.__root)
def _in(self, root):
if root is None:
return
if root is not None:
self._in(root.lchild)
print(str(root.value))
self._in(root.rchild)
def get_height(self):
print(str(self.height))
def __str__(self):
return self.in_order()
if __name__ == '__main__':
pass
