已知两个单链表A与B分别表示两个集合，其元素类型为int且递增排列，其头结点指针分别为a,b。求出A与B的交集，要求C同样以元素值递增的单链表形式储存。-Known two single chain A and B denote two collections whose elements of type int and ascending, the head node pointers are a, b. Find the intersection of A and B, C similarly to elements required by incrementing the value stored in the form of a single list.