数据结构题典012：链表求交集之二（ANSI C）

问题：已知两个按元素递增排列的链表，求二者交集，要求将结果放入第一个链表中。

/* * Intersection of two ordered linked lists. *  * fduan, Dec. 28, 2011. */void intersect_v2( link_list * lst_a, link_list lst_b ){node_ptr pa = *lst_a, pb = lst_b->next, p = NULL;while( pa->next != NULL && pb != NULL ){if( pa->next->data < pb->data ){p = pa->next;pa->next = p->next;free( p );}else if( pa->next->data > pb->data ){pb = pb->next;}else{pa = pa->next; pb = pb->next;}}while( pa->next != NULL ){p = pa->next;pa->next = p->next;free( p );}}