/*이중 연결리스트 Doubly LinkedList*/#include using namespace std; class DblList; class DblListNode{private: int data; DblListNode *left, *right;public: DblListNode(int element = 0, DblListNode *lNode = NULL, DblListNode *rNode = NULL) :data(element), left(lNode), right(rNode) { } friend class DblList; friend ostream &operatorright = first; //더미노드 } ~DblList() { DblListNode *delNode = first; //위치를 기억해두..