Diameter of Binary Tree
Given the root of a binary tree, return the length of its diameter: the longest path between any two nodes, measured in edges (the number of parent-child links along the path).
The path does not have to pass through the root. It may climb up from one node to some ancestor and come back down the other side to a second node, but it can't visit a node twice.
A tree with zero or one node has diameter 0.
Constraints
- The tree has between
0and10^4nodes. -100 <= Node.val <= 100
Examples
Example 1
Input: root = [1,2,3,4,5,null,6] Output: 4
The longest path is 4 → 2 → 1 → 3 → 6 (or 5 → 2 → 1 → 3 → 6): 4 edges.
Example 2
Input: root = [1,2] Output: 1
Two nodes joined by one edge.
Example 3
Input: root = [1,2,null,3,4,5,null,null,6,7,null,null,8] Output: 6
The longest path, 7 → 5 → 3 → 2 → 4 → 6 → 8, bends at node 2 and never touches the root: 6 edges.
JavaScript you'll use: Recursion, the call stack and memoization Functions, arrow functions and closures
/**
* Tree nodes are provided (you don't need to define them):
* class TreeNode { constructor(val = 0, left = null, right = null) { this.val = val; this.left = left; this.right = right; } }
*/
/**
* @param {TreeNode | null} root
* @return {number}
*/
function diameterOfBinaryTree(root) {
}
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