建立带头结点的双向循环链表L，插入，删除，逆置-double-way linked-list representation and implementation

单链表，单循环链表，双链表，循环双链表的实现，二叉树的遍历与实现。森林与树的转换以及图的深度广度遍历，邻接矩阵邻接表实现-Single list, round robin list, double-linked list, circular double-linked list implementation, and implementation of a binary tree traversal. Forest conversion, and the depth and breadth of