Tree : Top View Hackerrank Solution for explanation watch Video : Code: import java.util.*; import java.io.*; class Node { Node left; Node right; int data; Node( int data) { this .data = data; left = null; right = null; } } class Solution { /* class Node int data; Node left; Node right; */ static class NodeLevel{ Node node; Integer level; NodeLevel(Node node,Integer level){ this .node = node; this .level = level; } } public static void topView(Node root) { Queue<NodeLevel> q = new LinkedList<>(); TreeMap<Integer,Integer> tm = new TreeMap<>(); if (root==null){ return ; } q.add( new NodeLevel(root, 0 )); while (!q.isEmpty()){ NodeLevel temp = q.poll(); Node temp1 = temp.node; Intege