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C++ primer plus(第六版)编程练习答案第14章 C++中的代码重用

一、程序清单

studentc.h

// studentc.h -- defining a Student class using containment
#ifndef STUDENTC_H_
#define STUDENTC_H_

#include 
#include    
#include 
class Student
{
private:
	typedef std::valarray ArrayDb;
	std::string name;       // contained object
	ArrayDb scores;         // contained object
	// private method for scores output
	std::ostream & arr_out(std::ostream & os) const;
public:
	Student() : name("Null Student"), scores() {}
	explicit Student(const std::string & s)
		: name(s), scores() {}
	explicit Student(int n) : name("Nully"), scores(n) {}
	Student(const std::string & s, int n)
		: name(s), scores(n) {}
	Student(const std::string & s, const ArrayDb & a)
		: name(s), scores(a) {}
	Student(const char * str, const double * pd, int n)
		: name(str), scores(pd, n) {}
	~Student() {}
	double Average() const;
	const std::string & Name() const;
	double & operator[](int i);
	double operator[](int i) const;
	// friends
		// input
	friend std::istream & operator>>(std::istream & is,
		Student & stu);  // 1 word
	friend std::istream & getline(std::istream & is,
		Student & stu);     // 1 line
// output
	friend std::ostream & operator<<(std::ostream & os,
		const Student & stu);
};

#endif

studentc.cpp

// studentc.cpp -- Student class using containment
#include "studentc.h"
using std::ostream;
using std::endl;
using std::istream;
using std::string;

//public methods
double Student::Average() const
{
	if (scores.size() > 0)
		return scores.sum() / scores.size();
	else
		return 0;
}

const string & Student::Name() const
{
	return name;
}

double & Student::operator[](int i)
{
	return scores[i];         // use valarray::operator[]()
}

double Student::operator[](int i) const
{
	return scores[i];
}

// private method
ostream & Student::arr_out(ostream & os) const
{
	int i;
	int lim = scores.size();
	if (lim > 0)
	{
		for (i = 0; i < lim; i++)
		{
			os << scores[i] << " ";
			if (i % 5 == 4)
				os << endl;
		}
		if (i % 5 != 0)
			os << endl;
	}
	else
		os << " empty array ";
	return os;
}

// friends

// use string version of operator>>()
istream & operator>>(istream & is, Student & stu)
{
	is >> stu.name;
	return is;
}

// use string friend getline(ostream &, const string &)
istream & getline(istream & is, Student & stu)
{
	getline(is, stu.name);
	return is;
}

// use string version of operator<<()
ostream & operator<<(ostream & os, const Student & stu)
{
	os << "Scores for " << stu.name << ":\n";
	stu.arr_out(os);  // use private method for scores
	return os;
}

use_stuc.cpp

// use_stuc.cpp -- using a composite class
// compile with studentc.cpp
#include 
#include "studentc.h"
using std::cin;
using std::cout;
using std::endl;

void set(Student & sa, int n);

const int pupils = 3;
const int quizzes = 5;

int main()
{
	Student ada[pupils] =
	{ Student(quizzes), Student(quizzes), Student(quizzes) };

	int i;
	for (i = 0; i < pupils; ++i)
		set(ada[i], quizzes);
	cout << "\nStudent List:\n";
	for (i = 0; i < pupils; ++i)
		cout << ada[i].Name() << endl;
	cout << "\nResults:";
	for (i = 0; i < pupils; ++i)
	{
		cout << endl << ada[i];
		cout << "average: " << ada[i].Average() << endl;
	}
	cout << "Done.\n";
	// cin.get();

	return 0;
}

void set(Student & sa, int n)
{
	cout << "Please enter the student's name: ";
	getline(cin, sa);
	cout << "Please enter " << n << " quiz scores:\n";
	for (int i = 0; i < n; i++)
		cin >> sa[i];
	while (cin.get() != '\n')
		continue;
}
// use_stuc.cpp -- using a composite class
// compile with studentc.cpp
#include 
#include "studentc.h"
using std::cin;
using std::cout;
using std::endl;

void set(Student & sa, int n);

const int pupils = 3;
const int quizzes = 5;

int main()
{
	Student ada[pupils] =
	{ Student(quizzes), Student(quizzes), Student(quizzes) };

	int i;
	for (i = 0; i < pupils; ++i)
		set(ada[i], quizzes);
	cout << "\nStudent List:\n";
	for (i = 0; i < pupils; ++i)
		cout << ada[i].Name() << endl;
	cout << "\nResults:";
	for (i = 0; i < pupils; ++i)
	{
		cout << endl << ada[i];
		cout << "average: " << ada[i].Average() << endl;
	}
	cout << "Done.\n";
	// cin.get();

	return 0;
}

void set(Student & sa, int n)
{
	cout << "Please enter the student's name: ";
	getline(cin, sa);
	cout << "Please enter " << n << " quiz scores:\n";
	for (int i = 0; i < n; i++)
		cin >> sa[i];
	while (cin.get() != '\n')
		continue;
}

执行结果：

Please enter the student's name: Pat Roone
Please enter 5 quiz scores:
83 89 72 78 95
Please enter the student's name: Fleur O'Day
Please enter 5 quiz scores:
92 89 96 74 64

Student List:
Gil Bayts
Pat Roone
Fleur O'Day

Results:
Scores for Gil Bayts:
92 94 96 93 95
average: 94

Scores for Pat Roone:
83 89 72 78 95
average: 83.4

Scores for Fleur O'Day:
92 89 96 74 64
average: 83
Done.

studenti.h

// studenti.h -- defining a Student class using private inheritance
#ifndef STUDENTC_H_
#define STUDENTC_H_

#include 
#include 
#include    
class Student : private std::string, private std::valarray
{
private:
	typedef std::valarray ArrayDb;
	// private method for scores output
	std::ostream & arr_out(std::ostream & os) const;
public:
	Student() : std::string("Null Student"), ArrayDb() {}
	explicit Student(const std::string & s)
		: std::string(s), ArrayDb() {}
	explicit Student(int n) : std::string("Nully"), ArrayDb(n) {}
	Student(const std::string & s, int n)
		: std::string(s), ArrayDb(n) {}
	Student(const std::string & s, const ArrayDb & a)
		: std::string(s), ArrayDb(a) {}
	Student(const char * str, const double * pd, int n)
		: std::string(str), ArrayDb(pd, n) {}
	~Student() {}
	double Average() const;
	double & operator[](int i);
	double operator[](int i) const;
	const std::string & Name() const;
	// friends
		// input
	friend std::istream & operator>>(std::istream & is,
		Student & stu);  // 1 word
	friend std::istream & getline(std::istream & is,
		Student & stu);     // 1 line
// output
	friend std::ostream & operator<<(std::ostream & os,
		const Student & stu);
};

#endif

studenti.cpp

// studenti.cpp -- Student class using private inheritance
#include "studenti.h"
using std::ostream;
using std::endl;
using std::istream;
using std::string;

// public methods
double Student::Average() const
{
	if (ArrayDb::size() > 0)
		return ArrayDb::sum() / ArrayDb::size();
	else
		return 0;
}

const string & Student::Name() const
{
	return (const string &)*this;
}

double & Student::operator[](int i)
{
	return ArrayDb::operator[](i);         // use ArrayDb::operator[]()
}

double Student::operator[](int i) const
{
	return ArrayDb::operator[](i);
}

// private method
ostream & Student::arr_out(ostream & os) const
{
	int i;
	int lim = ArrayDb::size();
	if (lim > 0)
	{
		for (i = 0; i < lim; i++)
		{
			os << ArrayDb::operator[](i) << " ";
			if (i % 5 == 4)
				os << endl;
		}
		if (i % 5 != 0)
			os << endl;
	}
	else
		os << " empty array ";
	return os;
}

// friends
// use String version of operator>>()
istream & operator>>(istream & is, Student & stu)
{
	is >> (string &)stu;
	return is;
}

// use string friend getline(ostream &, const string &)
istream & getline(istream & is, Student & stu)
{
	getline(is, (string &)stu);
	return is;
}

// use string version of operator<<()
ostream & operator<<(ostream & os, const Student & stu)
{
	os << "Scores for " << (const string &)stu << ":\n";
	stu.arr_out(os);  // use private method for scores
	return os;
}

use_stui.cpp

// use_stui.cpp -- using a class with private inheritance
// compile with studenti.cpp
#include 
#include "studenti.h"
using std::cin;
using std::cout;
using std::endl;

void set(Student & sa, int n);

const int pupils = 3;
const int quizzes = 5;

int main()
{
	Student ada[pupils] =
	{ Student(quizzes), Student(quizzes), Student(quizzes) };

	int i;
	for (i = 0; i < pupils; i++)
		set(ada[i], quizzes);
	cout << "\nStudent List:\n";
	for (i = 0; i < pupils; ++i)
		cout << ada[i].Name() << endl;
	cout << "\nResults:";
	for (i = 0; i < pupils; i++)
	{
		cout << endl << ada[i];
		cout << "average: " << ada[i].Average() << endl;
	}
	cout << "Done.\n";
	// cin.get();
	return 0;
}

void set(Student & sa, int n)
{
	cout << "Please enter the student's name: ";
	getline(cin, sa);
	cout << "Please enter " << n << " quiz scores:\n";
	for (int i = 0; i < n; i++)
		cin >> sa[i];
	while (cin.get() != '\n')
		continue;
}

执行结果：

Please enter the student's name: Pat Roone
Please enter 5 quiz scores:
83 89 72 78 95
Please enter the student's name: Fleur O'Day
Please enter 5 quiz scores:
92 89 96 74 64

Student List:
Gil Bayts
Pat Roone
Fleur O'Day

Results:
Scores for Gil Bayts:
92 94 96 93 95
average: 94

Scores for Pat Roone:
83 89 72 78 95
average: 83.4

Scores for Fleur O'Day:
92 89 96 74 64
average: 83
Done.

ERROR解决：

“初始化”: 无法从“const char [6]”转换为“char *”

将 worker0.cpp中的：

char * Singer::pv[] = { "other", "alto", "contralto",
"soprano", "bass", "baritone", "tenor" };

（进行强制类型转换）修改为：

char * Singer::pv[] = {(char*)"other", (char*)"alto", (char*)"contralto",
(char*)"soprano", (char*)"bass", (char*)"baritone", (char*)"tenor"};

worker0.h

// worker0.h  -- working classes
#ifndef WORKER0_H_
#define WORKER0_H_

#include 

class Worker   // an abstract base class
{
private:
	std::string fullname;
	long id;
public:
	Worker() : fullname("no one"), id(0L) {}
	Worker(const std::string & s, long n)
		: fullname(s), id(n) {}
	virtual ~Worker() = 0;   // pure virtual destructor
	virtual void Set();
	virtual void Show() const;
};

class Waiter : public Worker
{
private:
	int panache;
public:
	Waiter() : Worker(), panache(0) {}
	Waiter(const std::string & s, long n, int p = 0)
		: Worker(s, n), panache(p) {}
	Waiter(const Worker & wk, int p = 0)
		: Worker(wk), panache(p) {}
	void Set();
	void Show() const;
};

class Singer : public Worker
{
protected:
	enum {
		other, alto, contralto, soprano,
		bass, baritone, tenor
	};
	enum { Vtypes = 7 };
private:
	static char *pv[Vtypes];    // string equivs of voice types
	int voice;
public:
	Singer() : Worker(), voice(other) {}
	Singer(const std::string & s, long n, int v = other)
		: Worker(s, n), voice(v) {}
	Singer(const Worker & wk, int v = other)
		: Worker(wk), voice(v) {}
	void Set();
	void Show() const;
};

#endif

worker0.cpp

// worker0.cpp -- working class methods
#include "worker0.h"
#include 
using std::cout;
using std::cin;
using std::endl;
// Worker methods

// must implement virtual destructor, even if pure
Worker::~Worker() {}

void Worker::Set()
{
	cout << "Enter worker's name: ";
	getline(cin, fullname);
	cout << "Enter worker's ID: ";
	cin >> id;
	while (cin.get() != '\n')
		continue;
}

void Worker::Show() const
{
	cout << "Name: " << fullname << "\n";
	cout << "Employee ID: " << id << "\n";
}

// Waiter methods
void Waiter::Set()
{
	Worker::Set();
	cout << "Enter waiter's panache rating: ";
	cin >> panache;
	while (cin.get() != '\n')
		continue;
}

void Waiter::Show() const
{
	cout << "Category: waiter\n";
	Worker::Show();
	cout << "Panache rating: " << panache << "\n";
}

// Singer methods

//char * Singer::pv[] = { "other", "alto", "contralto",
//			"soprano", "bass", "baritone", "tenor" };

char * Singer::pv[] = { (char*)"other", (char*)"alto", (char*)"contralto",
			(char*)"soprano", (char*)"bass", (char*)"baritone", (char*)"tenor" };

void Singer::Set()
{
	Worker::Set();
	cout << "Enter number for singer's vocal range:\n";
	int i;
	for (i = 0; i < Vtypes; i++)
	{
		cout << i << ": " << pv[i] << "   ";
		if (i % 4 == 3)
			cout << endl;
	}
	if (i % 4 != 0)
		cout << endl;
	while (cin >> voice && (voice < 0 || voice >= Vtypes))
		cout << "Please enter a value >= 0 and < " << Vtypes << endl;
	while (cin.get() != '\n')
		continue;
}

void Singer::Show() const
{
	cout << "Category: singer\n";
	Worker::Show();
	cout << "Vocal range: " << pv[voice] << endl;
}

worktest.cpp

// worktest.cpp -- test worker class hierarchy
#include 
#include "worker0.h"
const int LIM = 4;
int main()
{
	Waiter bob("Bob Apple", 314L, 5);
	Singer bev("Beverly Hills", 522L, 3);
	Waiter w_temp;
	Singer s_temp;

	Worker * pw[LIM] = { &bob, &bev, &w_temp, &s_temp };

	int i;
	for (i = 2; i < LIM; i++)
		pw[i]->Set();
	for (i = 0; i < LIM; i++)
	{
		pw[i]->Show();
		std::cout << std::endl;
	}
	// std::cin.get();
	return 0;
}

执行结果：

Enter worker's name: Waldo Dropmaster
Enter worker's ID: 442
Enter waiter's panache rating: 3
Enter worker's name: Sylvie Sirenne
Enter worker's ID: 555
Enter number for singer's vocal range:
0: other   1: alto   2: contralto   3: soprano
4: bass   5: baritone   6: tenor
3
Category: waiter
Name: Bob Apple
Employee ID: 314
Panache rating: 5

Category: singer
Name: Beverly Hills
Employee ID: 522
Vocal range: soprano

Category: waiter
Name: Waldo Dropmaster
Employee ID: 442
Panache rating: 3

Category: singer
Name: Sylvie Sirenne
Employee ID: 555
Vocal range: soprano

workermi.h

// workermi.h  -- working classes with MI
#ifndef WORKERMI_H_
#define WORKERMI_H_

#include 

class Worker   // an abstract base class
{
private:
	std::string fullname;
	long id;
protected:
	virtual void Data() const;
	virtual void Get();
public:
	Worker() : fullname("no one"), id(0L) {}
	Worker(const std::string & s, long n)
		: fullname(s), id(n) {}
	virtual ~Worker() = 0; // pure virtual function
	virtual void Set() = 0;
	virtual void Show() const = 0;
};

class Waiter : virtual public Worker
{
private:
	int panache;
protected:
	void Data() const;
	void Get();
public:
	Waiter() : Worker(), panache(0) {}
	Waiter(const std::string & s, long n, int p = 0)
		: Worker(s, n), panache(p) {}
	Waiter(const Worker & wk, int p = 0)
		: Worker(wk), panache(p) {}
	void Set();
	void Show() const;
};

class Singer : virtual public Worker
{
protected:
	enum {
		other, alto, contralto, soprano,
		bass, baritone, tenor
	};
	enum { Vtypes = 7 };
	void Data() const;
	void Get();
private:
	static char *pv[Vtypes];    // string equivs of voice types
	int voice;
public:
	Singer() : Worker(), voice(other) {}
	Singer(const std::string & s, long n, int v = other)
		: Worker(s, n), voice(v) {}
	Singer(const Worker & wk, int v = other)
		: Worker(wk), voice(v) {}
	void Set();
	void Show() const;
};

// multiple inheritance
class SingingWaiter : public Singer, public Waiter
{
protected:
	void Data() const;
	void Get();
public:
	SingingWaiter() {}
	SingingWaiter(const std::string & s, long n, int p = 0,
		int v = other)
		: Worker(s, n), Waiter(s, n, p), Singer(s, n, v) {}
	SingingWaiter(const Worker & wk, int p = 0, int v = other)
		: Worker(wk), Waiter(wk, p), Singer(wk, v) {}
	SingingWaiter(const Waiter & wt, int v = other)
		: Worker(wt), Waiter(wt), Singer(wt, v) {}
	SingingWaiter(const Singer & wt, int p = 0)
		: Worker(wt), Waiter(wt, p), Singer(wt) {}
	void Set();
	void Show() const;
};

#endif

workermi.cpp

// workermi.cpp -- working class methods with MI
#include "workermi.h"
#include 
using std::cout;
using std::cin;
using std::endl;
// Worker methods
Worker::~Worker() { }

// protected methods
void Worker::Data() const
{
	cout << "Name: " << fullname << endl;
	cout << "Employee ID: " << id << endl;
}

void Worker::Get()
{
	getline(cin, fullname);
	cout << "Enter worker's ID: ";
	cin >> id;
	while (cin.get() != '\n')
		continue;
}

// Waiter methods
void Waiter::Set()
{
	cout << "Enter waiter's name: ";
	Worker::Get();
	Get();
}

void Waiter::Show() const
{
	cout << "Category: waiter\n";
	Worker::Data();
	Data();
}

// protected methods
void Waiter::Data() const
{
	cout << "Panache rating: " << panache << endl;
}

void Waiter::Get()
{
	cout << "Enter waiter's panache rating: ";
	cin >> panache;
	while (cin.get() != '\n')
		continue;
}

// Singer methods

//char * Singer::pv[Singer::Vtypes] = { "other", "alto", "contralto",
//			"soprano", "bass", "baritone", "tenor" };

char * Singer::pv[] = { (char*)"other", (char*)"alto", (char*)"contralto",
			(char*)"soprano", (char*)"bass", (char*)"baritone", (char*)"tenor" };
void Singer::Set()
{
	cout << "Enter singer's name: ";
	Worker::Get();
	Get();
}

void Singer::Show() const
{
	cout << "Category: singer\n";
	Worker::Data();
	Data();
}

// protected methods
void Singer::Data() const
{
	cout << "Vocal range: " << pv[voice] << endl;
}

void Singer::Get()
{
	cout << "Enter number for singer's vocal range:\n";
	int i;
	for (i = 0; i < Vtypes; i++)
	{
		cout << i << ": " << pv[i] << "   ";
		if (i % 4 == 3)
			cout << endl;
	}
	if (i % 4 != 0)
		cout << '\n';
	while (cin >> voice && (voice < 0 || voice >= Vtypes))
		cout << "Please enter a value >= 0 and < " << Vtypes << endl;
	while (cin.get() != '\n')
		continue;
}

// SingingWaiter methods
void SingingWaiter::Data() const
{
	Singer::Data();
	Waiter::Data();
}

void SingingWaiter::Get()
{
	Waiter::Get();
	Singer::Get();
}

void SingingWaiter::Set()
{
	cout << "Enter singing waiter's name: ";
	Worker::Get();
	Get();
}

void SingingWaiter::Show() const
{
	cout << "Category: singing waiter\n";
	Worker::Data();
	Data();
}

workmi.cpp

// workmi.cpp -- multiple inheritance
// compile with workermi.cpp
#include 
#include 
#include "workermi.h"
const int SIZE = 5;

int main()
{
	using std::cin;
	using std::cout;
	using std::endl;
	using std::strchr;

	Worker * lolas[SIZE];

	int ct;
	for (ct = 0; ct < SIZE; ct++)
	{
		char choice;
		cout << "Enter the employee category:\n"
			<< "w: waiter  s: singer  "
			<< "t: singing waiter  q: quit\n";
		cin >> choice;
		while (strchr("wstq", choice) == NULL)
		{
			cout << "Please enter a w, s, t, or q: ";
			cin >> choice;
		}
		if (choice == 'q')
			break;
		switch (choice)
		{
		case 'w':   lolas[ct] = new Waiter;
			break;
		case 's':   lolas[ct] = new Singer;
			break;
		case 't':   lolas[ct] = new SingingWaiter;
			break;
		}
		cin.get();
		lolas[ct]->Set();
	}

	cout << "\nHere is your staff:\n";
	int i;
	for (i = 0; i < ct; i++)
	{
		cout << endl;
		lolas[i]->Show();
	}
	for (i = 0; i < ct; i++)
		delete lolas[i];
	cout << "Bye.\n";
	// cin.get();
	// cin.get();
	return 0;
}

执行结果：

Enter the employee category:
w: waiter  s: singer  t: singing waiter  q: quit
w
Enter waiter's name: Wally Slipshod
Enter worker's ID: 1040
Enter waiter's panache rating: 4
Enter the employee category:
w: waiter  s: singer  t: singing waiter  q: quit
s
Enter singer's name: Sinclair Parma
Enter worker's ID: 1044
Enter number for singer's vocal range:
0: other   1: alto   2: contralto   3: soprano
4: bass   5: baritone   6: tenor
5
Enter the employee category:
w: waiter  s: singer  t: singing waiter  q: quit
t
Enter singing waiter's name: Natasha Gargalova
Enter worker's ID: 1021
Enter waiter's panache rating: 6
Enter number for singer's vocal range:
0: other   1: alto   2: contralto   3: soprano
4: bass   5: baritone   6: tenor
3
Enter the employee category:
w: waiter  s: singer  t: singing waiter  q: quit
q

Here is your staff:

Category: waiter
Name: Wally Slipshod
Employee ID: 1040
Panache rating: 4

Category: singer
Name: Sinclair Parma
Employee ID: 1044
Vocal range: baritone

Category: singing waiter
Name: Natasha Gargalova
Employee ID: 1021
Vocal range: soprano
Panache rating: 6
Bye.

stacktp.h

// stacktp.h -- a stack template
#ifndef STACKTP_H_
#define STACKTP_H_
template 
class Stack
{
private:
	enum { MAX = 10 };    // constant specific to class
	Type items[MAX];    // holds stack items
	int top;            // index for top stack item
public:
	Stack();
	bool isempty();
	bool isfull();
	bool push(const Type & item); // add item to stack
	bool pop(Type & item);        // pop top into item
};

template 
Stack::Stack()
{
	top = 0;
}

template 
bool Stack::isempty()
{
	return top == 0;
}

template 
bool Stack::isfull()
{
	return top == MAX;
}

template 
bool Stack::push(const Type & item)
{
	if (top < MAX)
	{
		items[top++] = item;
		return true;
	}
	else
		return false;
}

template 
bool Stack::pop(Type & item)
{
	if (top > 0)
	{
		item = items[--top];
		return true;
	}
	else
		return false;
}

#endif

stacktem.cpp

// stacktem.cpp -- testing the template stack class
#include 
#include 
#include 
#include "stacktp.h"
using std::cin;
using std::cout;

int main()
{
	Stack st;   // create an empty stack
	char ch;
	std::string po;
	cout << "Please enter A to add a purchase order,\n"
		<< "P to process a PO, or Q to quit.\n";
	while (cin >> ch && std::toupper(ch) != 'Q')
	{
		while (cin.get() != '\n')
			continue;
		if (!std::isalpha(ch))
		{
			cout << '\a';
			continue;
		}
		switch (ch)
		{
		case 'A':
		case 'a': cout << "Enter a PO number to add: ";
			cin >> po;
			if (st.isfull())
				cout << "stack already full\n";
			else
				st.push(po);
			break;
		case 'P':
		case 'p': if (st.isempty())
			cout << "stack already empty\n";
				  else {
			st.pop(po);
			cout << "PO #" << po << " popped\n";
			break;
		}
		}
		cout << "Please enter A to add a purchase order,\n"
			<< "P to process a PO, or Q to quit.\n";
	}
	cout << "Bye\n";
	// cin.get();
	// cin.get();
	return 0;
}

执行结果:

Please enter A to add a purchase order,
P to process a PO, or Q to quit.
A
Enter a PO number to add: red911porsche
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
A
Enter a PO number to add: blueR8audi
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
A
Enter a PO number to add: silver747boeing
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
P
PO #silver747boeing popped
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
P
PO #blueR8audi popped
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
P
PO #red911porsche popped
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
P
stack already empty
Please enter A to add a purchase order,
P to process a PO, or Q to quit.
Q
Bye

stcktp1.h

// stcktp1.h -- modified Stack template
#ifndef STCKTP1_H_
#define STCKTP1_H_

template 
class Stack
{
private:
    enum {SIZE = 10};    // default size
    int stacksize;
    Type * items;       // holds stack items
    int top;            // index for top stack item
public:
    explicit Stack(int ss = SIZE);
    Stack(const Stack & st);
    ~Stack() { delete [] items; }
    bool isempty() { return top == 0; }
    bool isfull() { return top == stacksize; }
    bool push(const Type & item);   // add item to stack
    bool pop(Type & item);          // pop top into item
    Stack & operator=(const Stack & st);
};

template 
Stack::Stack(int ss) : stacksize(ss), top(0)
{
    items = new Type [stacksize];
}

template 
Stack::Stack(const Stack & st)
{
    stacksize = st.stacksize;
    top = st.top;
    items = new Type [stacksize];
    for (int i = 0; i < top; i++)
        items[i] = st.items[i];
}

template 
bool Stack::push(const Type & item)
{
    if (top < stacksize)
    {
        items[top++] = item;
        return true;
    }
    else
        return false;
}

template 
bool Stack::pop(Type & item)
{
    if (top > 0)
    {
        item = items[--top];
        return true;
    }
    else
        return false;
}

template 
Stack & Stack::operator=(const Stack & st)
{
    if (this == &st)
        return *this;
    delete [] items;
    stacksize = st.stacksize;
    top = st.top;
    items = new Type [stacksize];
    for (int i = 0; i < top; i++)
        items[i] = st.items[i];
    return *this; 
}

#endif

stkoptr1.cpp

// stkoptr1.cpp -- testing stack of pointers
#include 
#include      // for rand(), srand()
#include        // for time()
#include "stcktp1.h"
const int Num = 10;
int main()
{
    std::srand(std::time(0)); // randomize rand()
    std::cout << "Please enter stack size: ";
    int stacksize;
    std::cin >> stacksize;
// create an empty stack with stacksize slots
    Stack st(stacksize); 

// in basket
    const char * in[Num] = {
            " 1: Hank Gilgamesh", " 2: Kiki Ishtar",
            " 3: Betty Rocker", " 4: Ian Flagranti",
            " 5: Wolfgang Kibble", " 6: Portia Koop",
            " 7: Joy Almondo", " 8: Xaverie Paprika",
            " 9: Juan Moore", "10: Misha Mache"
            };
 // out basket
    const char * out[Num];

    int processed = 0;
    int nextin = 0;
    while (processed < Num)
    {
        if (st.isempty())
            st.push(in[nextin++]);
        else if (st.isfull())
            st.pop(out[processed++]);
        else if (std::rand() % 2  && nextin < Num)   // 50-50 chance
            st.push(in[nextin++]);
        else
            st.pop(out[processed++]);
    }
    for (int i = 0; i < Num; i++)
        std::cout << out[i] << std::endl;

    std::cout << "Bye\n";
    // std::cin.get();
    // std::cin.get();
	return 0; 
}

执行结果：

Please enter stack size: 5
 1: Hank Gilgamesh
 4: Ian Flagranti
 6: Portia Koop
 8: Xaverie Paprika
 9: Juan Moore
10: Misha Mache
 7: Joy Almondo
 5: Wolfgang Kibble
 3: Betty Rocker
 2: Kiki Ishtar
Bye

Please enter stack size: 5
 2: Kiki Ishtar
 1: Hank Gilgamesh
 3: Betty Rocker
 4: Ian Flagranti
 6: Portia Koop
 9: Juan Moore
10: Misha Mache
 8: Xaverie Paprika
 7: Joy Almondo
 5: Wolfgang Kibble
Bye

arraytp.h

//arraytp.h  -- Array Template
#ifndef ARRAYTP_H_
#define ARRAYTP_H_

#include 
#include 

template 
class ArrayTP
{
private:
	T ar[n];
public:
	ArrayTP() {};
	explicit ArrayTP(const T & v);
	virtual T & operator[](int i);
	virtual T operator[](int i) const;
};

template 
ArrayTP::ArrayTP(const T & v)
{
	for (int i = 0; i < n; i++)
		ar[i] = v;
}

template 
T & ArrayTP::operator[](int i)
{
	if (i < 0 || i >= n)
	{
		std::cerr << "Error in array limits: " << i
			<< " is out of range\n";
		std::exit(EXIT_FAILURE);
	}
	return ar[i];
}

template 
T ArrayTP::operator[](int i) const
{
	if (i < 0 || i >= n)
	{
		std::cerr << "Error in array limits: " << i
			<< " is out of range\n";
		std::exit(EXIT_FAILURE);
	}
	return ar[i];
}

#endif

twod.cpp

// twod.cpp -- making a 2-d array
#include 
#include "arraytp.h"
int main(void)
{
	using std::cout;
	using std::endl;
	ArrayTP sums;
	ArrayTP aves;
	ArrayTP< ArrayTP, 10> twodee;


	int i, j;

	for (i = 0; i < 10; i++)
	{
		sums[i] = 0;
		for (j = 0; j < 5; j++)
		{
			twodee[i][j] = (i + 1) * (j + 1);
			sums[i] += twodee[i][j];
		}
		aves[i] = (double)sums[i] / 5;
	}
	for (i = 0; i < 10; i++)
	{
		for (j = 0; j < 5; j++)
		{
			cout.width(2);
			cout << twodee[i][j] << ' ';
		}
		cout << ": sum = ";
		cout.width(3);
		cout << sums[i] << ", average = " << aves[i] << endl;
	}

	cout << "Done.\n";
	// std::cin.get();
	return 0;
}

执行结果：

 1  2  3  4  5 : sum =  15, average = 3
 2  4  6  8 10 : sum =  30, average = 6
 3  6  9 12 15 : sum =  45, average = 9
 4  8 12 16 20 : sum =  60, average = 12
 5 10 15 20 25 : sum =  75, average = 15
 6 12 18 24 30 : sum =  90, average = 18
 7 14 21 28 35 : sum = 105, average = 21
 8 16 24 32 40 : sum = 120, average = 24
 9 18 27 36 45 : sum = 135, average = 27
10 20 30 40 50 : sum = 150, average = 30
Done.

pairs.cpp

// pairs.cpp -- defining and using a Pair template
#include 
#include 
template 
class Pair
{
private:
	T1 a;
	T2 b;
public:
	T1 & first();
	T2 & second();
	T1 first() const { return a; }
	T2 second() const { return b; }
	Pair(const T1 & aval, const T2 & bval) : a(aval), b(bval) { }
	Pair() {}
};

template
T1 & Pair::first()
{
	return a;
}
template
T2 & Pair::second()
{
	return b;
}

int main()
{
	using std::cout;
	using std::endl;
	using std::string;
	Pair ratings[4] =
	{
		Pair("The Purpled Duck", 5),
		Pair("Jaquie's Frisco Al Fresco", 4),
		Pair("Cafe Souffle", 5),
		Pair("Bertie's Eats", 3)
	};

	int joints = sizeof(ratings) / sizeof(Pair);
	cout << joints << endl;//输出joints的值
	cout << "Rating:\t Eatery\n";
	for (int i = 0; i < joints; i++)
		cout << ratings[i].second() << ":\t "
		<< ratings[i].first() << endl;
	cout << "Oops! Revised rating:\n";
	ratings[3].first() = "Bertie's Fab Eats";
	ratings[3].second() = 6;
	cout << ratings[3].second() << ":\t "
		<< ratings[3].first() << endl;
	// std::cin.get();
	return 0;
}

执行结果：

4
Rating:  Eatery
5:       The Purpled Duck
4:       Jaquie's Frisco Al Fresco
5:       Cafe Souffle
3:       Bertie's Eats
Oops! Revised rating:
6:       Bertie's Fab Eats

tempmemb.cpp

// tempmemb.cpp -- template members
#include 
using std::cout;
using std::endl;

template 
class beta
{
private:
	template   // nested template class member
	class hold
	{
	private:
		V val;
	public:
		hold(V v = 0) : val(v) {}
		void show() const { cout << val << endl; }
		V Value() const { return val; }
	};
	hold q;             // template object
	hold n;           // template object
public:
	beta(T t, int i) : q(t), n(i) {}
	template   // template method
	U blab(U u, T t) { return (n.Value() + q.Value()) * u / t; }
	void Show() const { q.show(); n.show(); }
};

int main()
{
	beta guy(3.5, 3);
	cout << "T was set to double\n";
	guy.Show();
	cout << "V was set to T, which is double, then V was set to int\n";
	cout << guy.blab(10, 2.3) << endl;
	cout << "U was set to int\n";
	cout << guy.blab(10.0, 2.3) << endl;
	cout << "U was set to double\n";
	cout << "Done\n";
	// std::cin.get();
	return 0;
}

执行结果：

T was set to double
3.5
3
V was set to T, which is double, then V was set to int
28
U was set to int
28.2609
U was set to double
Done

stacktp.h

// stacktp.h -- a stack template
#ifndef STACKTP_H_
#define STACKTP_H_
template 
class Stack
{
private:
	enum { MAX = 10 };    // constant specific to class
	Type items[MAX];    // holds stack items
	int top;            // index for top stack item
public:
	Stack();
	bool isempty();
	bool isfull();
	bool push(const Type & item); // add item to stack
	bool pop(Type & item);        // pop top into item
};

template 
Stack::Stack()
{
	top = 0;
}

template 
bool Stack::isempty()
{
	return top == 0;
}

template 
bool Stack::isfull()
{
	return top == MAX;
}

template 
bool Stack::push(const Type & item)
{
	if (top < MAX)
	{
		items[top++] = item;
		return true;
	}
	else
		return false;
}

template 
bool Stack::pop(Type & item)
{
	if (top > 0)
	{
		item = items[--top];
		return true;
	}
	else
		return false;
}

#endif

tempparm.cpp

// tempparm.cpp ?templates as parameters
#include 
#include "stacktp.h"

template

A	B	公有派生还是私有派生合适
class Bear	class PolarBear	公有派生，因为北极熊也是一种熊，is-a的关系
class Kitchen	class Home	私有派生，因为家中有厨房，has-a的关系
class Person	class Programmer	公有派生，因为程序员也是人，is-a的关系
class Person	class HorseAndJockey	私有派生，因为马和驯马师的组合包人，has-a的关系
class Person, class Automobile	class Driver	人是公有的，人与司机是is-a关系；车是私有的，车与司机是has-a的关系

C++ primer plus(第六版)编程练习答案第14章 C++中的代码重用

一、程序清单

studentc.h

studentc.cpp

use_stuc.cpp

studenti.h

studenti.cpp

use_stui.cpp

ERROR解决：

worker0.h

worker0.cpp

worktest.cpp

workermi.h

workermi.cpp

workmi.cpp

stacktp.h

stacktem.cpp

stcktp1.h

stkoptr1.cpp

arraytp.h

twod.cpp

pairs.cpp

tempmemb.cpp

stacktp.h

tempparm.cpp

frnd2tmp.cpp

tmp2tmp.cpp

manyfrnd.cpp

二、复习题

三、编程练习

你可能感兴趣的:(c++,开发语言)

C++ primer plus(第六版)编程练习答案 第14章 C++中的代码重用

一、程序清单

studentc.h

studentc.cpp

use_stuc.cpp

studenti.h

studenti.cpp

use_stui.cpp

ERROR解决：

worker0.h

worker0.cpp

worktest.cpp

workermi.h

workermi.cpp

workmi.cpp

stacktp.h

stacktem.cpp

stcktp1.h

stkoptr1.cpp

arraytp.h

twod.cpp

pairs.cpp

tempmemb.cpp

stacktp.h

tempparm.cpp

frnd2tmp.cpp

tmp2tmp.cpp

manyfrnd.cpp

二、复习题

三、编程练习

你可能感兴趣的:(c++,开发语言)

C++ primer plus(第六版)编程练习答案第14章 C++中的代码重用