C语言队列

Queue.h

#ifndef _QUEUE_H_
#define _QUEUE_H_
#include 

typedef int Item;

#define MAXQUEUE 10

typedef struct node
{
	Item item;
	struct node* next; 
}Node;

typedef struct queue
{
	Node* front;       //记录头部
	Node* rear;        //记录尾部
	int items;         //记录项数
}Queue;

//队列初始化为空
void InitializeQueue(Queue* pq);

//检查队列是否以满
bool QueueIsFull(const Queue* pq);

//检查队列是否为空
bool QueueIsEmtpy(const Queue* pq);

//确定队列中的项数
int QueueItemCount(const Queue* pq);

//在队列末尾添加项
bool EnQueue(Item item, Queue* pq);

//从队列的开头删除项
bool DeQueue(Item* pitem, Queue* pq);

//清空队列
void EmptyTheQueue(Queue* pq);

#endif

Queue.cpp

#include 
#include 
#include "queue.h"

static void CopyToNode(Item item, Node* pn);
static void CopyToItem(Node* pn, Item* pi);

void InitializeQueue(Queue* pq)   //初始化
{
	pq->front = NULL;
	pq->rear = NULL;
	pq->items = 0;
}

bool QueueIsFull(const Queue* pq)  //判断是否已满  10
{
	return pq->items == MAXQUEUE;
}

bool QueueIsEmtpy(const Queue* pq)  //检查队列是否为空
{
	return pq->items == 0;
}

int QueueItemCount(const Queue* pq)  //确定队列中的项数
{
	return pq->items;
}

bool EnQueue(Item item, Queue* pq)  //在末尾添加项  item=1;
{
	Node* pnew = {};

	if (QueueIsFull(pq))
		return false;
	pnew = (Node*)malloc(sizeof(Node));
	if (pnew == NULL)
	{
		fprintf(stderr, "Unable to allocate memory!n");
		exit(1);
	}

	CopyToNode(item, pnew);
	pnew->next == NULL;
	if (QueueIsEmtpy(pq))
	{
		pq->front = pnew;
	}
	else
	{
		pq->rear->next = pnew;      
	}
	pq->rear = pnew;              
	pq->items++;

	return true;
}

bool DeQueue(Item* pitem, Queue* pq)  //从队列开头删除项
{
	Node* pt = {};

	if (QueueIsEmtpy(pq))
		return false;

	CopyToItem(pq->front, pitem);
	pt = pq->front;
	pq->front = pq->front->next;
	free(pt);

	pq->items--;
	if (pq->items == 0)
		pq->rear = NULL;

	return true;
}

void EmptyTheQueue(Queue* pq)      //清空队列
{
	Item dummy;
	while (!QueueIsEmtpy(pq))
		DeQueue(&dummy, pq);
}

void CopyToNode(Item item, Node* pn)  //拷贝到节点
{
	pn->item = item;
}

void CopyToItem(Node* pn, Item* pi)    //拷贝到项目
{
	*pi = pn->item;
}

UseQueue.cpp

#include 
#include "queue.h"

int main(void)
{
	char ch;
	Item temp;
	Queue line;

	InitializeQueue(&line);
	puts("Testing the Queue interface. Type a to add a value,");
	puts("type d to delete a value, and type q to quit.");

	while ((ch = getchar()) != 'q')
	{
		if (ch != 'a' && ch != 'd')
		{
			printf("incorrect inputn");
			continue;
		}
			
		if (ch == 'a')
		{
			printf("Integer to add: ");
			scanf_s("%d", &temp);

			if (!QueueIsFull(&line))
			{
				printf("Putting %d into queuen", temp);
				EnQueue(temp, &line);
			}
			else
				puts("Queue is full!");
		}
		else
		{
			if (QueueIsEmtpy(&line))
				puts("Noting to delete!");
			else
			{
				DeQueue(&temp, &line);
				printf("Removing %d from queuen", temp);
			}
		}
		printf("%d items in queuen", QueueItemCount(&line));
		puts("Type a to add, d to delete, q to quit:");
	}

	EmptyTheQueue(&line);
	puts("bye!");

	return 0;
}