# Diameter of Binary Tree

Given a binary tree, you need to compute 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.

Example: Given a binary tree

          1
/ \
2   3
/ \
4   5


Return 3, which is the length of the path [4,2,1,3] or [5,2,1,3].

Note: The length of path between two nodes is represented by the number of edges between them.

Solution:

MAX-DEPTH

class Solution {
public:
int depth(TreeNode* root){
if(root == NULL) return 0;
return max(depth(root->left), depth(root->right))+1;
}

int diameterOfBinaryTree(TreeNode* root) {
if(root == NULL) return 0;
return max(max(diameterOfBinaryTree(root->left), diameterOfBinaryTree(root->right)), depth(root->left)+depth(root->right));
}
};