LeetCode@543_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].

java:

/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
int max = 0;
public int diameterOfBinaryTree(TreeNode root)
{
deptMax(root);
return max;

}

private int deptMax(TreeNode root)
{
if(root == null) return 0;

int left = deptMax(root.left);
int right = deptMax(root.right);

max = Math.max(left+right,max);
return Math.max(left, right)+1;

}
}