LeftView.java

package BinaryTree;
import java.util.*;
public class LeftView {
    static ArrayList<TreeNode> ans = new ArrayList<>();
    public static void main(String args[]) {

        TreeNode  root = new TreeNode(1);
        root . left = new TreeNode(3);
        root . left . left = new TreeNode(5);
        root . left . left . left = new TreeNode(7);
        root . right = new TreeNode(2);
        root . right . right = new TreeNode(4);
        root . right . right . right = new TreeNode(6);

        leftView(root,0);
        for(TreeNode node:ans)
        {
            System.out.print(node.data + " ");
        }
    }
    public static void leftView(TreeNode root,int level)
    {
        if(root == null)return;
        if(ans.size() == level)
        {
            ans.add(root);
        }
        leftView(root.left , level + 1);
        leftView(root.right , level +1);
    }
}