Queue--队列(c语言简单实现)

 1 #include<stdlib.h>

 2 typedef char ele;

 3 typedef struct node{

 4     ele e;

 5     struct node     qnode;

 6 }QNode,*Qptr;

 7 

 8 typedef struct{

 9     Qptr front;

10     Qptr rear;

11 }Queue;

12 

13 //初始化空队列

14 void initQueue(Queue *q){

15     q->front=q->rear=(QNode *)malloc(sizeof(QNode));

16     if(!q->front)exit(0);

17     q->front->qnode=NULL;

18 }

19 

20 //插入队列

21 void insert(Queue *q,ele e){

22     QNode node = (QNode *)malloc(sizeof(QNode));

23     if(!node)exit(0);

24     node->e=e;

25     node->qnode=NULL;

26     q->rear->qnode=node;

27     q->rear=node;

28 }

29 

30 //out queue

31 ele delQueue(Queue *q){

32     if(q->front==q->rear)return NULL;

33     QNode node = q->front->qnode;

34     ele e = node->e;

35     q->front->qnode=node->qnode;

36     if(q->rear==q)q->rear=q->front;

37     free(node);

38     return e;

39 }

40 

41 //clear queue

42 void clearQueue(Queue *q){

43     if(q->front==q->rear)return ;

44     while(q->front!=q->rear){

45         QNode node = q->front->qnode;

46         q->front->qnode = node->qnode;

47         free(node);

48     }

49 }