### LeetCode Challenge #543. Diameter of Binary Tree

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.

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`
##### Video Solution
###### Java Solution
```				```
class Solution {
int dia = 0 ;
public int height(TreeNode root){
if(root == null){
return 0 ;
}
int lh = height(root.left);
int rh = height(root.right);
// currNode diameter = lh + rh
dia = Math.max(lh+rh , dia  );

return Math.max(lh , rh) +1 ;
}
public int diameterOfBinaryTree(TreeNode root) {
if(root == null){
return 0 ;
}
int h = height(root);
return dia ;
}
}
```
```