Binary Tree Maximum Path Sum
Detailed guide and Python implementation for the 'Binary Tree Maximum Path Sum' problem.
Problem Statement
A path in a binary tree is a sequence of nodes where each pair of adjacent nodes in the sequence has an edge connecting them. A node can only appear in the sequence at most once. Note that the path does not need to pass through the root.
The path sum of a path is the sum of the node's values in the path.
Given the root of a binary tree, return the maximum path sum of any non-empty path.
The tree is represented as a level-order list. Implement a function maxPathSum(root: list) -> int.
- •The number of nodes in the tree is in the range [1, 30000]
- •-1000 <= Node.val <= 1000
Examples
[1,2,3]
6
The optimal path is 2 -> 1 -> 3 with a path sum of 2 + 1 + 3 = 6.
[-10,9,20,None,None,15,7]
42
The optimal path is 15 -> 20 -> 7 with a path sum of 15 + 20 + 7 = 42.
[-3]
-3
The only path is the single node -3.
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
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