c语言 给定两个集合A和B，求集合A和集合B的并集。

struct Link *Union(struct Link *head1, struct Link *head2) { struct Link *p1 = head1->next, *p2 = head2->next; struct Link *head, *p, *q; head = (struct Link *)malloc(sizeof(struct Link)); head->next = NULL; p = head;