Construct Complete Binary Tree from its Linked List Representation

// C# program to create a Complete Binary tree
// from its Linked List Representation

using System;
using System.Collections.Generic;

class Lnode {
    public int data;
    public Lnode next;

    public Lnode(int value) {
        data = value;
        next = null;
    }
}

class Tnode {
    public int data;
    public Tnode left, right;

    public Tnode(int value) {
        data = value;
        left = null;
        right = null;
    }
}

class GfG {
  
    // Converts a given linked list representing a complete binary tree into the
    // linked representation of a binary tree.
    static Tnode convert(Lnode head) {
        if (head == null) {
            return null;
        }

        // Queue to store the parent nodes
        Queue<Tnode> q = new Queue<Tnode>();

        // The first node is always the root node,
        // and add it to the queue
        Tnode root = new Tnode(head.data);
        q.Enqueue(root);

        // Move the pointer to the next node
        head = head.next;

        // Until the end of the linked list is reached,
        // do the following steps
        while (head != null) {
          
            // Take the parent node from the queue
            // and remove it from the queue
            Tnode parent = q.Dequeue();

            Tnode leftChild = null, rightChild = null;

            // Create left child
            if (head != null) {
                leftChild = new Tnode(head.data);
                q.Enqueue(leftChild);
                head = head.next;
            }

            // Create right child
            if (head != null) {
                rightChild = new Tnode(head.data);
                q.Enqueue(rightChild);
                head = head.next;
            }

            // Assign the left and right children
          	// of the parent
            parent.left = leftChild;
            parent.right = rightChild;
        }

        return root;
    }

    // Level Order Traversal of the binary tree
    static void LevelOrderTraversal(Tnode root) {
        if (root == null) {
            return;
        }

        // Queue to hold nodes at each level
        Queue<Tnode> q = new Queue<Tnode>();
        q.Enqueue(root);

        while (q.Count > 0) {
            Tnode currNode = q.Dequeue();

            // Print the current node's data
            Console.Write(currNode.data + " ");

            // Push the left and right children
            // of the current node to the queue
            if (currNode.left != null) {
                q.Enqueue(currNode.left);
            }
            if (currNode.right != null) {
                q.Enqueue(currNode.right);
            }
        }
    }

    static void Main(string[] args) {
      
        // Create linked list : 10->12->15->25->30->36
        Lnode head = new Lnode(10);
        head.next = new Lnode(12);
        head.next.next = new Lnode(15);
        head.next.next.next = new Lnode(25);
        head.next.next.next.next = new Lnode(30);
        head.next.next.next.next.next = new Lnode(36);

        Tnode root = convert(head);
        LevelOrderTraversal(root);
    }
}