public static void print(TreeLinkNode node) {
    	if (null != node) {
    		System.out.print(node.val);
    		System.out.print("[");
    		if (null == node.left) {
    			System.out.print("null");
    		} else {
    			System.out.print(node.left.val);
    		}
    		System.out.print(",");
    		if (null == node.right) {
    			System.out.print("null");
    		} else {
    			System.out.print(node.right.val);
    		}
    		System.out.print(",");
    		if (null == node.next) {
    			System.out.print("null");
    		} else {
    			System.out.print(node.next.val);
    		}
    		System.out.println("]");
    		print(node.left);
    		print(node.right);
    	}
    }