typedef struct Node{ unsigned long int id; void *value; struct Node *next; struct Node *last; }Node; typedef struct List{ Node *head; Node *tail; unsigned long int length; }List; List *init_list(); Node *init_node(); int insertInHead(List *p_list, Node *p_node); int insertInTail(List *p_list, Node *p_node); int removeById(List *p_list, unsigned long id); int removeByNode(List *p_list, Node *p_node); int popFromHead(List *p_list); int popFromTail(List *p_list); unsigned long int len(List *p_list); Node *findById(List *p_list, unsigned long int id); Node *findByValue(List *p_list, char type[], void *value); int insertInHead(List *p_list, Node *p_node){ p_list->head->last = p_node; //p_node->last = NULL; p_node->next = p_list->head; p_list->head = p_node; return 0; } int insertInTail(List *p_list, Node *p_node){ p_list->tail->next = p_node; //p_node->next = NULL; p_node->last = p_list->tail; p_list->tail = p_node; return 0; }