SinglyLinkedListNode *newNode = (SinglyLinkedListNode*)malloc(sizeof(SinglyLinkedListNode));
newNode->data = data;

if (head == NULL) {
    return newNode;
}

if (position == 0) {
   newNode->next = head;
   return newNode;
}

while((currentNode->next)!=position)
{
    currentNode=currentNode->next;
}

newNode->next = currentNode->next;
currentNode->next = newNode;

return head;