What is wrong in my code?

#1

import java.util.*;

public class Main {

Scanner scn = new Scanner(System.in);

public class BinaryTree {
	private class Node {
		int data;
		Node left;
		Node right;
	}

	private Node root;
	private int size;

	public BinaryTree() {
		this.takeInput();
	}

	public void takeInput() {
		int ht=scn.nextInt();
		LinkedList<Node> queue = new LinkedList<>();
		root = new Node();
		root.data = scn.nextInt();
		queue.addLast(root);

		while (!queue.isEmpty()) {
			Node node = queue.removeFirst();

			if (node.data == -1) {
				continue;
			}

			node.left = new Node();
			node.right = new Node();
			int item1=scn.nextInt();
			
			node.left.data = item1;
			
			int item2=scn.nextInt();
			
			node.right.data = item2;
			
			queue.addLast(node.left);
			queue.addLast(node.right);
		}

	}

	private class VOpair {
		Node node;
		int vl;

		VOpair(Node node, int vl) {
			this.node = node;
			this.vl = vl;
		}

	}

	public void verticalorderdisplay() {
		HashMap<Integer, ArrayList<Integer>> map = new HashMap<>();

		Queue<VOpair> q = new LinkedList<>();
		VOpair sp = new VOpair(root, 0);
		q.add(sp);
		while (!q.isEmpty()) {
			VOpair rp = q.remove();
			if (!map.containsKey(rp.vl)) {
				map.put(rp.vl, new ArrayList<>());
			}
			map.get(rp.vl).add(rp.node.data);

			if (rp.node.left != null && rp.node.left.data != -1) {
				VOpair np = new VOpair(rp.node.left, rp.vl - 1);
				q.add(np);
			}
			if (rp.node.right != null && rp.node.right.data != -1) {
				VOpair np = new VOpair(rp.node.right, rp.vl + 1);
				q.add(np);
			}

		}
		ArrayList<Integer> keys = new ArrayList<>(map.keySet());
		Collections.sort(keys);
		for (int val : keys) {
			System.out.println(map.get(val));
		}
	}
}

public static void main(String[] args) {
	Main m = new Main();
	BinaryTree bt = m.new BinaryTree();
	bt.verticalorderdisplay();
}

}

#2

Your output format:

[4]
[2]
[1, 5, 6]
[3, 8]
[7]
[9]

print the output without any square brackets or commas

#3

ok i have done it thanks

#4

i have other doubts also plz reply on them

#5

yes please mark this doubt as resolved :slight_smile: