ugly

public int maxDepth(TreeNode root){
        if(root == null){
            return 0;
        }
        else if(root.left == null && root.right == null){
            return 0;
        }
        else{
            return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));
        }
    }

    public int diameterOfBinaryTree(TreeNode root) {
        if(root == null){
            return 0;
        }
        else if(root.left == null && root.right == null){
            return 0;
        }
        int leftPath = root.left == null ? 0 : 1 + maxDepth(root.left);
        int rightPath = root.right == null ? 0 : 1 + maxDepth(root.right);
        return Math.max(Math.max(leftPath + rightPath, diameterOfBinaryTree(root.left)), diameterOfBinaryTree(root.right));
    }