Class Solution

src/com/blankj/easy/_0543/Solution.java:14–34

author: Blankj blog : http://blankj.com time : 2017/10/13 desc :

 * </pre>
 */
public class Solution {
    int max = 0;

    public int diameterOfBinaryTree(TreeNode root) {
        helper(root);
        return max;
    }

    private int helper(TreeNode root) {
        if (root == null) return 0;
        int l = helper(root.left);
        int r = helper(root.right);
        if (l + r > max) max = l + r;
        return Math.max(l, r) + 1;
    }

    public static void main(String[] args) {
        Solution solution = new Solution();
        System.out.println(solution.diameterOfBinaryTree(TreeNode.createTestData("[1,2,3,4,5]")));
    }
}