链式队列实现

typedef struct list//创建队列中的链式结构
{
	datatype data;//数据域
	struct list* next;//指针域
}list;

typedef struct queue//创建队列
{
	list* front;//队头
	list* rear;//队尾
}queue;

void initqueue(queue* q)//初始化队列
{
	q->front = q->rear = (list*)malloc(sizeof(list));//使队头和队尾指向同一块内存区域
	if (q->front == NULL)
	{
		printf("error\n");
		return;
	}
	q->front->next = NULL;//队头（队尾）的下一个节点都是空
}

bool isempty(queue* q)
{
	if (q->front == q->rear || q->front->next == NULL)
	{
		return true;
	}
	return false;
}

void enqueue(queue* q)
{
	printf("输入入队的元素值\n");
	datatype element;
	scanf("%d", &element);
	list* newnode = (list*)malloc(sizeof(list));
	if (newnode == NULL)
	{
		printf("error\n");
		return;
	}
	newnode->next = NULL;
	newnode->data = element;//12345
	q->rear->next = newnode;//         12345
	q->rear = newnode;    //          f    r
}

datatype outqueue(queue* q)
{
	if (q->front == q->rear || q->front->next == NULL)
	{
		printf("empty\n");
		exit(1);
	}
	list* pointer;
	datatype temp;
	pointer = q->front->next;
	temp = pointer->data;
	q->front->next = pointer->next;           //12345
	if (pointer == q->rear)   //               f
	{                              //          r 
		//printf("empty\n");
		q->rear = q->front;
	}
	return temp;
}

int main()
{
	queue q;
	initqueue(&q);//初始化队列
	bool flag = isempty(&q);
	if (!flag)
	{
		printf("error\n");
		return -1;
	}
	int i = 0;
	printf("要加入几个元素\n");
	int n;
	scanf("%d", &n);
	for (i = 0; i < n; i++)
	{
		enqueue(&q);
	}
	for (i = 0; i < 5; i++)
	{
		printf("%d ", outqueue(&q));
	}
	return 0;
}