【C语言】【数据结构】循环队列的基本操作（创建、入队、出队、队长、队头、遍历、应用）

创建空的循环队列，并实现入队、出队、返回队列的长度、返回队头元素、队列的遍历等基本算法。

#include <stdio.h>
#include <stdlib.h>
#define ERROR 0
#define OK 1
#define MAXQSIZE 100

typedef int Status;

typedef int QElemType;
typedef struct{
	QElemType *base;
	int front, rear;
}SqQueue;

Status InitQueue(SqQueue & );				//空队列
Status EnQueue(SqQueue & , QElemType );		//入队
Status DeQueue(SqQueue & , QElemType & );	//出队
int QueueLength(SqQueue );					//队列长度
Status GetHead(SqQueue , QElemType & );		//队头
Status QueueTraverse(SqQueue );				//遍历

//应用
Status bank_simulation();		//银行客户平均等待时间



int main()
{
	SqQueue Q;
	int a;
	QElemType e;
	
	if(!InitQueue(Q)) printf("Create Error!\n");
	while(1)
	{
		printf("1:Enter\n2:Delete\n3:Get the front\n4:Return the length of the queue\n5:Load the queue\n0:Exit\nPlease choose:\n");
		scanf("%d",&a);
		switch(a)
		{
			case 1: printf("Enter the element: ");
					scanf("%d", &e);
					if(!EnQueue(Q,e)) printf("Enter Error!\n\n");
					else printf("The element is %d successfully entered!\n\n", e);
					break;
			case 2: if(!DeQueue(Q,e)) printf("Delete Error!\n\n");
					else printf("The element is %d successfully deleted!\n\n", e);
					break;
			case 3: if(!GetHead(Q,e)) printf("Get Head Error!\n\n");
					else printf("The head of the queue is %d!\n\n", e);
					break;
			case 4: printf("The length of the queue is %d\n\n", QueueLength(Q));
					break;
			case 5: printf("The queue is ");
					QueueTraverse(Q);
					printf("\n");
					break;
			case 0: return OK;
			
		}
	}
}

Status InitQueue(SqQueue &Q)
{
	Q.base = (QElemType *) malloc (MAXQSIZE * sizeof(QElemType));
	if(!Q.base) return ERROR;
	Q.front = Q.rear =0;
	return OK;
}

Status EnQueue(SqQueue &Q, QElemType e)
{
	if((Q.rear+1)%MAXQSIZE == Q.front) return ERROR;
	Q.base[Q.rear] = e;
	Q.rear = (Q.rear+1) % MAXQSIZE;
	return OK;
}

Status DeQueue(SqQueue &Q, QElemType &e)
{
	if(Q.front == Q.rear) return ERROR;
	e = Q.base[Q.front];
	Q.front = (Q.front+1) % MAXQSIZE;
	return OK;
}

int QueueLength(SqQueue Q)
{
	return((Q.rear - Q.front + MAXQSIZE) % MAXQSIZE);
}

Status GetHead(SqQueue Q, QElemType &e)
{
	if(Q.front == Q.rear) return ERROR;
	e = Q.base[Q.front];
	return OK;
}

Status QueueTraverse(SqQueue Q)
{
	int i;
	
	if(Q.front == Q.rear) printf("The queue is empty!\n");
	else
		for(i=Q.front; i!=Q.rear; i=(i+1)%MAXQSIZE)
			printf("%d ", Q.base[i]);
	printf("\n");
	return OK;
}

队列的应用：银行客户平均等待时间（一个窗口）
到达时间 arrivaltime
办理业务时间 duration
离开时间 departure
等待时间 waittime
总等待时间 total

输入格式
第一行：一天内的客户总人数n
第二行：第一个客户的到达时刻和需要办理业务的时间
第三行：第二个客户的到达时刻和需要办理业务的时间
……
第n行：第n - 1个客户的到达时刻和需要办理业务的时间
第n + 1行：第n 个客户的到达时刻和需要办理业务的时间

输出格式
第一行：所有客户的平均等待时间（精确到小数点后2位）

Status bank_simulation()
{
	SqQueue Q;
	int n, i;
	int arrivaltime, duration, departure, waittime, total=0;
	float agv;
	
	if(!InitQueue(Q)) printf("Create Error!\n");
	printf("请输入一天内的客户总人数: ");
	scanf("%d", &n);
	for(i=1; i<=n; i++)
	{
		printf("请输入第%d个客户的到达时刻和需要办理业务的时间: \n", i);
		scanf("%d %d", &arrivaltime, &duration);
		EnQueue(Q, arrivaltime);
		EnQueue(Q, duration);
	}
	DeQueue(Q, arrivaltime);
	DeQueue(Q, duration);
	departure = duration + arrivaltime;
	while(Q.front != Q.rear)
	{
		DeQueue(Q, arrivaltime);
		waittime = departure - arrivaltime;
		DeQueue(Q, duration);
		departure += duration;
		total += waittime;
	}
	agv = total*1.0 / n ;
	printf("平均等待时间：%.2f\n", agv);
}