带头节点的 链式存储队列基本操作

#include<stdio.h>
#include<malloc.h>
typedef char ElemType;
typedef struct LinkNode
{
	ElemType data;
	struct LinkNode *next;
}LinkNode;
typedef struct
{
	struct LinkNode *front,*rear;
}LinkQueue;
void InitQueue(LinkQueue &q)
{
	q.rear=q.front=(LinkNode*)malloc(sizeof(LinkNode));
	q.front->next=NULL;
}
bool IsEmpty(LinkQueue q)
{
	if(q.front==q.rear)
		return true;
	else
		return false;
}
void EnQueue(LinkQueue &q,ElemType e)
{
	LinkNode *s=(LinkNode*)malloc(sizeof(LinkNode));
	s->data=e;
	s->next=NULL;
	q.rear->next=s;
	q.rear=s;
}
bool DeQueue(LinkQueue &q,ElemType &e)
{
	if(q.rear==q.front)
		return false;
	LinkNode *p=q.front->next;
	e=p->data;
	q.front->next=p->next;
	if(q.rear==p)
		q.front=q.rear;
	free(p);
	return true;
}
bool HeadQueue(LinkQueue q,ElemType &e)
{
	if(q.front==q.rear)
		return e='?';
	e=q.front->next->data;
	return true;
}
void main()
{
	LinkQueue q;
	InitQueue(q);
	printf("The Queue is %s\n",IsEmpty(q)?"Empty":"UnEmpty");
	ElemType e;
	HeadQueue(q,e);
	printf("Head_Queue is %c\n",e);
	EnQueue(q,'a');
	EnQueue(q,'b');
	EnQueue(q,'c');
	HeadQueue(q,e);
	printf("Head_Queue is %c\n",e);
	DeQueue(q,e);
	HeadQueue(q,e);
	printf("Head_Queue is %c\n",e);
	DeQueue(q,e);
	HeadQueue(q,e);
	printf("Head_Queue is %c\n",e);
	DeQueue(q,e);
	HeadQueue(q,e);
	printf("Head_Queue is %c\n",e);
	printf("The Queue is %s\n",IsEmpty(q)?"Empty":"UnEmpty");
}