// cpp code SinglyLinkedListNode* insertNodeAtTail(SinglyLinkedListNode* head, int data) { //ll doestnt exist

    if(head==NULL){
        head= new SinglyLinkedListNode(data);
        return head;
    }
    //ll already exist
    else{
     SinglyLinkedListNode* temp=head;
     while(temp->next!=NULL){
        temp=temp->next;
     }
     temp->next=new SinglyLinkedListNode(data);
     return head;
    }

}