To design a can achieve the intersection of two sets and and set operations, program. Basic requirements: a collection of elements limited to alphabetic characters' a '-' z ', 'a' - 'z' or numeric characters' 0 '~' 9 '. In the collection does not allow duplicate elements, if repeated input, process can be repeated; Used singly linked lists as the problem of data structure related issues, algorithm and data structure in c/c + +