O(NlgK)问题队列实现文件C语言

/* Queue.c -- 队列实现文件 */ #include "Queue.h" /* 局部函数声明 */ static QueueNode * makeNode_Q (const Item item) ; /* 接口函数定义 */ BOOL Initialize_Q (Queue * const pq) { *pq = (struct queue *) malloc (sizeof (struct queue)) ; if (NULL == *pq) return FALSE ; (*pq) -> front = (*pq) -> rear = NULL ; (*pq) -> current = 0 ; return TRUE ; } BOOL IsEmpty_Q (const Queue * const pq) { if (0 == (*pq) -> current) return TRUE ; else return FALSE ; } BOOL EnQueue_Q (const Queue * const pq, const Item item) { QueueNode * newNode ; newNode = makeNode_Q (item) ; if (NULL == newNode) return FALSE ; if (IsEmpty_Q (pq)) (*pq) -> front = (*pq) -> rear = newNode ; else { (*pq) -> rear -> next = newNode ; (*pq) -> rear = newNode ; } (*pq) -> current++ ; return TRUE ; } BOOL DeQueue_Q (const Queue * const pq, Item * const messenger) { QueueNode * record ; if (IsEmpty_Q (pq)) return FALSE ; record = (*pq) -> front ; *messenger = record -> item ; (*pq) -> front = record -> next ; if (record == (*pq) -> rear) (*pq) -> rear = NULL ; free (record) ; (*pq) -> current-- ; return TRUE ; } void Release_Q (const Queue * const pq) { QueueNode * record ; while ((*pq) -> front != NULL) { record = (*pq) -> front ; (*pq) -> front = record -> next ; free (record) ; } free (*pq) ; } /* 局部函数定义 */ static QueueNode * makeNode_Q (const Item item) { QueueNode * newNode ; newNode = (QueueNode *) malloc (sizeof (QueueNode)) ; if (NULL == newNode) return NULL ; newNode -> item = item ; newNode -> next = NULL ; return newNode ; }