链式队列的基本运算
链式队列的定义
#include <stdio.h>
#include <malloc.h>
typedef char ElemType;
typedef struct QNode
{
ElemType data;
struct QNode *next;
} QType;
typedef struct qptr
{
QType *front,*rear;
} LinkQueue;
初始化队列
void InitQueue(LinkQueue *&lq)
{
lq=(LinkQueue *)malloc(sizeof(LinkQueue));
lq->rear=lq->front=NULL;
}
入队运算
void EnQueue(LinkQueue *&lq,ElemType x)
{
QType *s;
s=(QType *)malloc(sizeof(QType));
s->data=x;s->next=NULL;
if (lq->front==NULL && lq->rear==NULL)
lq->rear=lq->front=s;
else
{
lq->rear->next=s;
lq->rear=s;
}
}
出队运算
int DeQueue(LinkQueue *&lq,ElemType &x)
{
QType *p;
if (lq->front==NULL && lq->rear==NULL)
return 0;
p=lq->front;
x=p->data;
if (lq->rear==lq->front)
lq->rear=lq->front=NULL;
else
lq->front=lq->front->next;
free(p);
return 1;
}
取队头元素运算
int GetHead(LinkQueue *lq,ElemType &x)
{
if (lq->front==NULL && lq->rear==NULL)
return 0;
x=lq->front->data;
return 1;
}
判断队空运算
int QueueEmpty(LinkQueue *lq)
{
if (lq->front==NULL && lq->rear==NULL)
return 1;
else
return 0;
}
main
void main()
{
LinkQueue *lq;
ElemType e;
InitQueue(lq);
printf("队%s\n",(QueueEmpty(lq)==1?"空":"不空"));
printf("a进队\n");EnQueue(lq,'a');
printf("b进队\n");EnQueue(lq,'b');
printf("c进队\n");EnQueue(lq,'c');
printf("d进队\n");EnQueue(lq,'d');
printf("队%s\n",(QueueEmpty(lq)==1?"空":"不空"));
GetHead(lq,e);
printf("队头元素:%c\n",e);
printf("出队次序:");
while (!QueueEmpty(lq))
{
DeQueue(lq,e);
printf("%c ",e);
}
printf("\n");
}