public static void topView(Node root) { if (root == null) { return;

}

Queue> queue = new LinkedList<>(); // Map to store the first node at each horizontal distance Map map = new TreeMap<>();

    // Start with the root node and horizontal distance 0
    queue.offer(new AbstractMap.SimpleEntry<>(root, 0));

    while (!queue.isEmpty()) {
        Map.Entry<Node, Integer> entry = queue.poll();
        Node node = entry.getKey();
        int horizontalDistance = entry.getValue();

        // If the horizontal distance is not yet in the map, add it
        if (!map.containsKey(horizontalDistance)) {
            map.put(horizontalDistance, node.data);
        }

        // If the node has a left child, enqueue it with horizontal distance - 1
        if (node.left != null) {
            queue.offer(new AbstractMap.SimpleEntry<>(node.left, horizontalDistance - 1));
        }

        // If the node has a right child, enqueue it with horizontal distance + 1
        if (node.right != null) {
            queue.offer(new AbstractMap.SimpleEntry<>(node.right, horizontalDistance + 1));
        }
    }

    // Print the top view by iterating over the map
    for (int value : map.values()) {
        System.out.print(value + " ");
    }
}