C++primer plus第六版课后编程练习答案12.5与12.6

bank是第五题的实现，bank1是第六题的实现

#ifndef QUEUE_H_
#define QUEUE_H_

class Customer
{
private:
int arrive;
int processtime;
public:
Customer(){arrive=processtime=0;}

void set(int when);
int when()const{return arrive;}
int ptime()const{return processtime;}
bool operator!=(const Customer &c)const;
bool operator==(const Customer &c)const;

};

typedef Customer Item;

class Queue
{
private:
struct Node{
Item item;
Node *next;
};
enum{Q_SIZE=10};

Node *front;
Node *rear;
int items;
const int qsize;
int first_start_time;

Queue(const Queue &q):qsize(0){}//
Queue &operator=(const Queue &q){return *this;}//使类不能被复制

public:
Queue(int qs=Q_SIZE);
//	Queue(Item &i);
~Queue();
void clearline();
bool isempty();
bool isfull();
bool insertqueue(const Item &i);
bool deletequeue(Item &i);
int queuecount()const;
int CusNumbefore(const Item &i)const;
void set_first_start_time(const int t);
int wait_time_min(const Item &i,const int t);//只有类成员函数后可加const，代表成员函数不能修改类的数据成员

};

#endif

#include<iostream>
#include "queue.h"
#include<cstdlib>//for rand()

using namespace std;

Queue::Queue(int qs):qsize(qs)
{
front=rear=0;
items=0;
first_start_time=0;
}

Queue::~Queue()
{
Node *temp;
while(front!=NULL)
{
temp=front;
front=front->next;
delete temp;
}
}

void Queue::clearline()
{
Node *temp;
while(front!=NULL)
{
temp=front;
front=front->next;
delete temp;
}
front=rear=0;
items=0;
first_start_time=0;
}

bool Queue::isempty()
{
return items==0;
}

bool Queue::isfull()
{
return items==qsize;
}

int Queue::queuecount()const
{
return items;
}

bool Queue::insertqueue(const Item &i)
{
if(isfull())
return false;
Node *add=new Node;
add->item=i;
add->next=NULL;
items++;
if(front==NULL)
front=add;
else
rear->next=add;
rear=add;
return true;
}

bool Queue::deletequeue(Item &i)
{
if(isempty())
return false;
i=front->item;
items--;
Node *temp=front;
front=front->next;
delete temp;
if(items==0)
rear=NULL;
return true;
}

int Queue::CusNumbefore(const Item &i)const
{
Node *temp=front;
int n=1;

cout<<temp->item.when()<<endl<<temp->item.ptime()<<endl;//显示客户的加入时间和处理时间
while(i!=temp->item)
{
if(temp==NULL)
return -1;
temp=temp->next;
n++;
}
return n;

}

void Queue::set_first_start_time(const int t)
{
first_start_time=t;
}

int Queue::wait_time_min(const Item &i,const int t)
{
if(CusNumbefore(i)==-1)
{
cout<<"顾客i不在队列当中"<<endl;
return 0;
}
else
{
Node *temp=front;
int wait_time=0;
while(temp->item!=i)
{
temp=temp->next;
wait_time+=temp->item.ptime();
}
return wait_time;

}
}

void Customer::set(int when)
{
processtime=rand()%3+1;
arrive=when;
}

bool Customer::operator!=(const Customer &c)const
{
if((arrive==c.arrive)&&(processtime==c.processtime))
return false;
return true;
}

bool Customer::operator==(const Customer &c)const
{
if((arrive==c.arrive)&&(processtime==c.processtime))
return true;
return false;
}

<pre name="code" class="cpp">#include<iostream>
#include<cstdlib>
#include<ctime>
#include "queue.h"

using namespace std;

const int MIN_PER_HR=60;

bool newcustomer(double x);

void bank();

void bank1();

int main()
{

bank1();

return 0;
}

bool newcustomer(double x)
{
return (rand()*x/RAND_MAX<1);
}

void bank()
{

srand(time(0));
cout<<"Case Study:Bank of Heather Automatic Teller\n";
//	cout<<"Enter maximum size of queue:";
int qs;
//	cin>>qs;
qs=10;
Queue line(qs);//输入队列最大长度

//	cout<<"Enter the number of simulation hours:";

int hours;
//	cin>>hours;
hours=100;
long cyclelimit=MIN_PER_HR*hours;//输入程序运行时间

//	cout<<"Enter the average number of customers per hour:";
double perhour;
//	cin>>perhour;//输入每小时到达的客户数
double min_per_cust;

Item temp;
long turnaways=0;
long customers=0;
long served=0;
long sum_line=0;
int  wait_time=0;
long line_wait=0;

double average_wait_time;

for(int i=1;i<105;i++)
{

turnaways=0;
customers=0;
served=0;
sum_line=0;
wait_time=0;
line_wait=0;

perhour=i;
min_per_cust=MIN_PER_HR/perhour;
for(int cycle=0;cycle<cyclelimit;cycle++)
{
if(newcustomer(min_per_cust))//判断有无新用户
{
if(line.isfull())
turnaways++;
else
{
customers++;
//				cout<<"插入一个新客户"<<endl;
temp.set(cycle);//用户到达时间
line.insertqueue(temp);//插入新用户

//				cout<<"现在时间"<<cycle<<endl;
//				cout<<customers<<"处理时间"<<temp.ptime()<<endl;

//				cout<<customers<<"位置:"<<line.CusNumbefore(temp)<<endl;
//				cout<<"wait_time="<<wait_time<<endl;
//				cout<<customers<<"等待时间:"<<(line.wait_time_min(temp,cycle)+wait_time)<<endl;
}
}
if((wait_time<=0)&&!(line.isempty()))
{
//		cout<<"删除一个客户"<<endl;
line.deletequeue(temp);
line.set_first_start_time(cycle);
wait_time=temp.ptime();
line_wait+=cycle-temp.when();
served++;
}
if(wait_time>0)
wait_time--;
sum_line+=line.queuecount();

//		cout<<"ATM运行时间结束"<<endl;

}

if(customers>0)
{
//		cout<<"customers accepted: "<<customers<<endl;
//		cout<<"  customers served: "<<served<<endl;
//		cout<<"         turnaways: "<<turnaways<<endl;
//		cout<<"average queue size: ";
//		cout.precision(2);
//		cout.setf(ios_base::fixed,ios_base::floatfield);
//		cout<<(double)sum_line/cyclelimit<<endl;
//		cout<<" average wait time: "
//			<<(double) line_wait/served<<" minutes\n";
average_wait_time=(double)(line_wait/served);
if(average_wait_time<=1)
{
cout<<perhour<<endl;
//		break;
}

line.clearline();//清空队列

}
else
cout<<"No customers!\n";

}
cout<<"Done!\n";

}

void bank1()
{
srand(time(0));
cout<<"Case Study:Bank of Heather Automatic Teller\n";
//	cout<<"Enter maximum size of queue:";
int qs;
//	cin>>qs;
qs=10;
Queue line1(qs);//输入队列最大长度
Queue line2(qs);

//	cout<<"Enter the number of simulation hours:";

int hours;
//	cin>>hours;
hours=100;
long cyclelimit=MIN_PER_HR*hours;//输入程序运行时间

//	cout<<"Enter the average number of customers per hour:";
double perhour;
//	cin>>perhour;//输入每小时到达的客户数
double min_per_cust;

Item temp;
long turnaways=0;
long customers=0;
long served=0;
long sum_line=0;
int  wait_time1=0;
int  wait_time2=0;
long line_wait=0;

double average_wait_time;

for(int i=1;i<100;i++)
{

turnaways=0;
customers=0;
served=0;
sum_line=0;
wait_time1=0;
wait_time2=0;
line_wait=0;

perhour=i;
min_per_cust=MIN_PER_HR/perhour;
for(int cycle=0;cycle<cyclelimit;cycle++)
{
if(newcustomer(min_per_cust))//判断有无新用户
{
if(line1.isfull()&&line2.isfull())
turnaways++;
else
{
customers++;
//				cout<<"插入一个新客户"<<endl;
temp.set(cycle);//用户到达时间
//				cout<<line1.queuecount()<<endl;
//				cout<<line2.queuecount()<<endl;
if(line1.queuecount()<=line2.queuecount())
{
//					cout<<"line1插入一个新客户"<<endl;
line1.insertqueue(temp);//当line1的队列人数小于等于line2时，向line1插入新用户
}
else
{
//					cout<<"line2插入一个新客户"<<endl;
line2.insertqueue(temp);//否则，向line2插入新用户
}

//				cout<<"现在时间"<<cycle<<endl;
//				cout<<customers<<"处理时间"<<temp.ptime()<<endl;

//				cout<<customers<<"位置:"<<line.CusNumbefore(temp)<<endl;
//				cout<<"wait_time="<<wait_time<<endl;
//				cout<<customers<<"等待时间:"<<(line.wait_time_min(t
4000
emp,cycle)+wait_time)<<endl;
}
}
if((wait_time1<=0)&&!(line1.isempty()))//处理line1的在队首的客户
{
//			cout<<"line1删除一个客户"<<endl;
line1.deletequeue(temp);
line1.set_first_start_time(cycle);
wait_time1=temp.ptime();
line_wait+=cycle-temp.when();
served++;
}

if((wait_time2<=0)&&!(line2.isempty()))//处理line2的在队首的客户
{
//		cout<<"line2删除一个客户"<<endl;
line2.deletequeue(temp);
line2.set_first_start_time(cycle);
wait_time2=temp.ptime();
line_wait+=cycle-temp.when();
served++;
}
if(wait_time1>0)
wait_time1--;
if(wait_time2>0)
wait_time2--;
sum_line+=line1.queuecount()+line2.queuecount();

//		cout<<"ATM运行时间结束"<<endl;

}

if(customers>0)
{
//		cout<<"customers accepted: "<<customers<<endl;
//		cout<<"  customers served: "<<served<<endl;
//		cout<<"         turnaways: "<<turnaways<<endl;
//		cout<<"average queue size: ";
//		cout.precision(2);
//		cout.setf(ios_base::fixed,ios_base::floatfield);
//		cout<<(double)sum_line/cyclelimit<<endl;
//		cout<<" average wait time: "
//			<<(double) line_wait/served<<" minutes\n";
average_wait_time=(double)(line_wait/served);
if(average_wait_time<=1)
{
cout<<perhour<<endl;
//		break;
}

line1.clearline();//清空队列
line2.clearline();//清空队列

}
else
cout<<"No customers!\n";

}
cout<<"Done!\n";

}