队列的基本操作（采用链式存储结构）

#include <stdio.h>
#include <stdlib.h>

#define TRUE 1
#define FALSE 0
#define ERROR -1

typedef int Status;
typedef char ElemType;
typedef struct qNode
{
ElemType data;
struct qNode *next;
} QNode,*QueuePtr;
typedef struct
{
QueuePtr front,rear;
} QueueLink;

Status InitQueue(QueueLink *q);
Status InsertQueue(QueueLink *q,ElemType e);
Status DeleteQueue(QueueLink *q,ElemType *e);
Status DestroyQueue(QueueLink *q);

int main(int argc,char **argv)
{
QueueLink q;
InitQueue(&q);
int i,j;
for(i=0;i<6;i++)
{
InsertQueue(&q,i+65);
}
char ch;
for(j=0;j<6;j++)
{
DeleteQueue(&q,&ch);
printf("%c,",ch);
}
printf("\n");
DestroyQueue(&q);
exit(0);
}

Status InitQueue(QueueLink *q)
{
q->front=q->rear=(QueuePtr)malloc(sizeof(QNode));
if(!q->front)
return ERROR;
q->front->next=NULL;
return TRUE;
}
//入队
Status InsertQueue(QueueLink *q,ElemType e)
{
QueuePtr p=(QueuePtr)malloc(sizeof(QNode));
if(!p)
return ERROR;
p->data=e;
p->next=NULL;
q->rear->next=p;
q->rear=p;
return TRUE;
}
//出对
Status DeleteQueue(QueueLink *q,ElemType *e)
{
if(q->front==q->rear)
return     FALSE;
QueuePtr p=q->front->next;
*e=p->data;
q->front->next=p->next;
if(q->rear==p)
q->rear=q->front;
free(p);
return TRUE;
}

Status DestroyQueue(QueueLink *q)
{
while(q->front)
{
q->rear=q->front->next;
free(q->front);
q->front=q->rear;
}
return TRUE;
}