How to print left view of binary tree in java

 If you are preparing for the technical interview then prepare this question . It is one of the most asked question in the interviews. In this problem you are given a binary tree and you have to print the left view of this tree. Suppose if this is our binary tree

Then our output must be : 1 2 4

Because if we are left hand side of the tree then we can only see 1 2 and 4 .

Java Code :

class Node{

int data;

Node left;

Node right;

Node(int data){

this.data=data;

this.left=null;

this.right=null;

}

}

class HindiCodingCommunity{

public static int maxLevel=0;

public static void PrintLeft(Node root,int level){

if(root==null){

return;

}

if(maxLevel<level){

System.out.println(root.data+" ");

maxLevel=level;

}

PrintLeft(root.left,level+1);

PrintLeft(root.right,level+1);

}

public static void printLeftView(Node root){

PrintLeft(root,1);

}

public static void main(String args[])

{

Node root = new Node(1);

root.left = new Node(2);

root.right= new Node(3);

root.left.left= new Node(4);

root.right.left= new Node(5);

root.right.right= new Node(6);

printLeftView(root);

}

}