URL: LeetCode Problem
Problem Description
Given the root of a binary tree, return the length of the diameter of the tree.
The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.
The length of a path between two nodes is represented by the number of edges between them.
Examples:
- Example 1:
Input: root = [1,2,3,4,5]
Output: 3
Explanation: 3 is the length of the path [4,2,1,3] or [5,2,1,3].
Constraints:
- The number of nodes in the tree is in the range [1, 104].
- 100 <= Node.val <= 100
Answer
Intuition
Approach
Complexity
Time complexity:
Space complexity:
Code
class Solution:
def diameterOfBinaryTree(self, root: Optional[TreeNode]) -> int:
self.diameter = 0
def recursion(node):
if not node: return 0
left = recursion(node.left)
right = recursion(node.right)
self.diameter = max(right+left, self.diameter)
return max(right, left) + 1
ans = recursion(root)
return self.diameter