<reponame>vinaykumar7686/Leetcode-August_Challenge
# Balanced Binary Tree

'''
Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as:

a binary tree in which the left and right subtrees of every node differ in height by no more than 1.

 

Example 1:


Input: root = [3,9,20,null,null,15,7]
Output: true
Example 2:


Input: root = [1,2,2,3,3,null,null,4,4]
Output: false
Example 3:

Input: root = []
Output: true
 

Constraints:

The number of nodes in the tree is in the range [0, 5000].
-104 <= Node.val <= 104
'''# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def isBalanced(self, root: TreeNode) -> bool:
        def helper(root):
            if not root:
                return 0
            
            left = helper(root.left)
            right = helper(root.right)
            
            if left == -1 or right == -1 or abs(left - right)>1:
                return -1
            
            return max(left, right)+1
            
        res = helper(root)
        
        return True if res!=-1 else False

# Balanced Binary Tree

'''
Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as:

a binary tree in which the left and right subtrees of every node differ in height by no more than 1.

 

Example 1:


Input: root = [3,9,20,null,null,15,7]
Output: true
Example 2:


Input: root = [1,2,2,3,3,null,null,4,4]
Output: false
Example 3:

Input: root = []
Output: true
 

Constraints:

The number of nodes in the tree is in the range [0, 5000].
-104 <= Node.val <= 104
'''# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def isBalanced(self, root: TreeNode) -> bool:
        def helper(root):
            if not root:
                return 0
            
            left = helper(root.left)
            right = helper(root.right)
            
            if left == -1 or right == -1 or abs(left - right)>1:
                return -1
            
            return max(left, right)+1
            
        res = helper(root)
        
        return True if res!=-1 else False
# Balanced Binary Tree Given a binary tree, determine if it is height-balanced.  For this problem, a height-balanced binary tree is defined as:  a binary tree in which the left and right subtrees of every node differ in height by no more than 1.     Example 1:   Input: root = [3,9,20,null,null,15,7] Output: true Example 2:   Input: root = [1,2,2,3,3,null,null,4,4] Output: false Example 3:  Input: root = [] Output: true    Constraints:  The number of nodes in the tree is in the range [0, 5000]. -104 <= Node.val <= 104 # class TreeNode: #     def __init__(self, val=0, left=None, right=None): #         self.val = val #         self.left = left #         self.right = right