Answers for "If we delete 20 from the above (2,4) tree, which node would be the final new root of the resultant tree"

binary tree deletion

/* This is just the deletion function you need to write the required code.
	Thank you. */

void deleteNode(Node *root, int data)
{
    if(root == NULL)
    {
        cout << "Tree is emptyn";
        return;
    }

    queue<Node*> q;
    q.push(root);

    while(!q.empty())
    {
        Node *temp = q.front();
        q.pop();

        if(temp->data == data)
        {
            Node *current = root;
            Node *prev;

            while(current->right != NULL)
            {
                prev = current;
                current = current->right;
            }

            temp->data = current->data;
            prev->right = NULL;
            free(current);

            cout << "Deletedn";

            return;
        }

        if(temp->left != NULL)
            q.push(temp->left);
        if(temp->right != NULL)
            q.push(temp->right);
    }

    cout << "Node not found for deletionn";
}