3.4.6

代码说明：

  单链表中的数据元素含有三种字符（字母、数字、其他字符），算法实现构造三个循环链表，是每个循环链表中只含有同一类字符，且利用原表中的结点空间作为这三个表的结点空间。(Singly linked lists of data element contains three characters (letters, Numbers and other characters), the algorithm constructs three circular linked list, each cycle list contains only the same type of character, and make use of the primary node space in a table as a node of the three table space.)