LeetCode: Populating Next Right Pointers in Each Node

/**
 * Created by hzhou on 4/27/15. [email protected]
 */
public class PopulatingNextRightPointersInEachNode {
    public void connect(TreeLinkNode root) {
        if (root == null) {
            return;
        }
        Stack<TreeLinkNode> stack = new Stack<TreeLinkNode>();
        stack.push(root);
        while (!stack.isEmpty()) {
            TreeLinkNode node = stack.pop();
            if (node.left != null) {
                stack.push(node.left);
                TreeLinkNode cursor = null;
                while (node != null) {
                    if (cursor != null) {
                        cursor.next = node.left;
                    }
                    node.left.next = node.right;
                    cursor = node.right;
                    node = node.next;
                }
            }
        }
    }
}