Learn AI Create the Future — with Pranay
Main site

LeetCode solutions

1092. Maximum Difference Between Node and Ancestor

My accepted Python solution to LeetCode problem 1092, Maximum Difference Between Node and Ancestor, running in 0ms.

  • Difficulty: Medium
  • Python
  • Runtime 0ms
  • Memory 18.8MB

Read the problem on LeetCode View on GitHub

The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.

Python

Accepted on LeetCode — runtime 0ms, memory 18.8MB, accepted 2026-01-02.

python
# 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 maxAncestorDiff(self, root: Optional[TreeNode]) -> int:
        def dfs(node, min_val, max_val):
            if not node:
                return max_val - min_val
            
            min_val = min(min_val, node.val)
            max_val = max(max_val, node.val)
            
            left = dfs(node.left, min_val, max_val)
            right = dfs(node.right, min_val, max_val)
            
            return max(left, right)
        
        return dfs(root, root.val, root.val)

Source