C++单链表中求指定元素最后出现的索引

//返回指定元素最后出现的索引template<typename T>int chain<T>::lastIndexOf(const T& theElement) const{chainNode<T>* currentNode = firstNode;chainNode<T>* tempNode;int index=0,i;do {i = index;do{currentNode = currentNode->next;index++;}while (currentNode != NULL&¤tNode->element != theElement);} while (index < listSize);if (i == 0){if (firstNode->element == theElement)return 0;elsereturn -1;}elsereturn i;}