HTMLify

// Vertical Traversal of Binary Tree java solution

//{ Driver Code Starts
//Initial Template for Java

//Contributed by Sudarshan Sharma
import java.util.LinkedList; 
import java.util.Queue; 
import java.io.*;
import java.util.*;

class Node{
    int data;
    Node left;
    Node right;
    Node(int data){
        this.data = data;
        left=null;
        right=null;
    }
}

class GfG {
    
    static Node buildTree(String str){
        
        if(str.length()==0 || str.charAt(0)=='N'){
            return null;
        }
        
        String ip[] = str.split(" ");
        // Create the root of the tree
        Node root = new Node(Integer.parseInt(ip[0]));
        // Push the root to the queue
        
        Queue<Node> queue = new LinkedList<>(); 
        
        queue.add(root);
        // Starting from the second element
        
        int i = 1;
        while(queue.size()>0 && i < ip.length) {
            
            // Get and remove the front of the queue
            Node currNode = queue.peek();
            queue.remove();
                
            // Get the current node's value from the string
            String currVal = ip[i];
                
            // If the left child is not null
            if(!currVal.equals("N")) {
                    
                // Create the left child for the current node
                currNode.left = new Node(Integer.parseInt(currVal));
                // Push it to the queue
                queue.add(currNode.left);
            }
                
            // For the right child
            i++;
            if(i >= ip.length)
                break;
                
            currVal = ip[i];
                
            // If the right child is not null
            if(!currVal.equals("N")) {
                    
                // Create the right child for the current node
                currNode.right = new Node(Integer.parseInt(currVal));
                    
                // Push it to the queue
                queue.add(currNode.right);
            }
            i++;
        }
        
        return root;
    }
    static void printInorder(Node root)
    {
        if(root == null)
            return;
            
        printInorder(root.left);
        System.out.print(root.data+" ");
        
        printInorder(root.right);
    }
    
	public static void main (String[] args) throws IOException{
	        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	        
	        int t=Integer.parseInt(br.readLine());
    
	        while(t-- > 0){
	            String s = br.readLine();
    	    	Node root = buildTree(s);
                Solution obj = new Solution();
                ArrayList <Integer> res = obj.verticalOrder(root);
                for (Integer num : res) System.out.print(num + " "); 
                System.out.println();
    	        
	        }
	}
}

// } Driver Code Ends


//User function Template for Java

class Pair {
    Node n;
    int x;
    
    Pair(Node n1, int x1) {
        n = n1;
        x = x1;
    }
}

class Solution {
    // Function to find the vertical order traversal of Binary Tree.
    static ArrayList<Integer> verticalOrder(Node root) {
        // add your code here
        TreeMap<Integer, LinkedList<Integer>> map = new TreeMap<>();
        Queue<Pair> q = new LinkedList<>();
        ArrayList<Integer> ans = new ArrayList<>();
        
        if (root == null) {
            return ans;
        } else {
            q.add(new Pair(root, 0));
        }
         
        while (!q.isEmpty()) {
            Pair p = q.poll();
            Node remn = p.n;
            int remv = p.x;
            if (!map.containsKey(remv)) {
                map.put(remv, new LinkedList<Integer>());
            }
            map.get(remv).add(remn.data);
            if (remn.left != null) {
                q.add(new Pair(remn.left, remv - 1));
            }
            if (remn.right != null) {
                q.add(new Pair(remn.right, remv + 1));
            }
        }
         
        for (LinkedList<Integer> list : map.values()) {
            ans.addAll(list);
        }
        
        return ans;
    }
}