Diameter of Binary Tree
Difficulty: EasyTopic: TreeDepth-First SearchBinary TreeLeetcode:543.Diameter of Binary TreeGiven 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.
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].
Example 2:
Input: root = [1,2]
Output: 1
Constraints:
- The number of nodes in the tree is in the range
[1, 104]. -100 <= Node.val <= 100
Solution
write solution in here
/**
* @param {TreeNode} root
* @return {number}
*/
var diameterOfBinaryTree = function(root) {
let res = 0
const reserve = function(root) {
if (!root) return null
let l = reserve(root.left),
r = reserve(root.right)
res = Math.max(res, l + r)
return Math.max(l, r) + 1
}
reserve(root)
return res
};