[C++知识库]C++ Primer Plus 第十四章答案 C++中的代码重用

复习题

//14.6
//1
公有，北极熊是一种熊
私有，家里有厨房
公有，程序员是一种人
私有，马和驯马师的组合包含一个人
人，公有，司机是一个人
汽车，私有，司机有汽车

//2
Gloam::Gloam(int g, const char* s) : fb(s), glip(g) {}
Gloam::Gloam(int g, const Frabjous& f) : fb(f), glip(g) {}
void Gloam::tell() {
	fb.tell();
	std::cout << "glib: " << glib >> endl;
}

//3
Gloam::Gloam(int g, const char* s) : Frabjous(s), glip(g) {}
Gloam::Gloam(int g, const Frabjous& f) : Frabjous(f), glip(g) {}
void Gloam::tell() {
	Frabjous::tell();
	std::cout << "glib: " << glib >> endl;
}

//4
class Stack<Worker*> {
private:
	enum { MAX = 10 };
	Worker* items[MAX];
	int top;
public:
	Stack();
	bool isempty();
	bool isfull();
	bool push()(const Workser*& item);
	bool pop(Worker*& item);
};

//5
ArrayTP<string>arr_str;
StackTP<ArrayTP<double>>sck_arr_db;
ArrayTP<StackTP<Worker*>>arr_stk_workerp;
4个

//6
如果两条继承路线有相同的祖先，则类中将包含祖先成员的两个拷贝
将祖先类作为虚基类可以解决这种问题

编程练习

第一题

#pragma once
//wine.h
#include<valarray>
#include<string>

template<class T1,class T2>
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() {}
};
class Wine {
private:
	typedef std::valarray<int> ArrayInt;
	typedef Pair<ArrayInt, ArrayInt> PairArray;
	std::string label;
	PairArray pair;
	int yr_num;
public:
	Wine() :label("None"), yr_num(0),pair() {};
	Wine(const char* l, int y, const int yr[], const int bot[]);
	Wine(const char* l, int y);
	void GetBottles();
	const std::string& Label()const;
	int sum()const;
	void show()const;
};



//wine.cpp
#include<iostream>
#include"wine.h"
using namespace std;
Wine::Wine(const char* l, int y, const int yr[], const int bot[])
	:label(l), yr_num(y) {
	ArrayInt a(y);
	ArrayInt b(y);
	for (int i = 0; i < y; i++) {
		a[i] = yr[i];
		b[i] = bot[i];
	}
	pair.first() = a;
	pair.second() = b;
}
Wine::Wine(const char* l, int y) :label(l), yr_num(y) {
	ArrayInt a(y);
	ArrayInt b(y);
	for (int i = 0; i < y; i++) {
		a[i] = 0;
		b[i] = 0;
	}
	pair.first() = a;
	pair.second() = b;
}
void Wine::GetBottles() {
	ArrayInt a(yr_num);
	ArrayInt b(yr_num);
	cout << "Enter " << label << " data for " << yr_num << " year(s):" << endl;
	for (int i = 0; i < yr_num; i++) {
		cout << "Enter year: ";
		cin >> a[i];
		cout << "Enter bottles for that years: ";
		cin >> b[i];
	}
	pair.first() = a;
	pair.second() = b;
}
const string& Wine::Label()const {
	return label;
}
int Wine::sum()const {
	int sum = 0;
	for (int i = 0; i < yr_num; i++)
		sum += pair.second()[i];
	return sum;
}
void Wine::show()const {
	cout << "Wine: " << label << endl;
	cout << "\tyear\tBottles" << endl;
	for (int i = 0; i < yr_num; i++)
		cout << "\t" << pair.first()[i] << "\t" << pair.second()[i] << endl;
}

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





//main.cpp
#include"wine.h"
#include<iostream>
using namespace std;
int main() {
	cout << "Enter name of wine: ";
	char lab[50];
	cin.getline(lab, 50);
	cout << "Enter number of years:";
	int years;
	cin >> years;
	Wine holding(lab, years);
	holding.GetBottles();
	holding.show();

	const int YEARS = 3;
	int y[YEARS] = { 1993,1995,1998 };
	int b[YEARS] = { 48,60,72 };
	Wine more("Gushing Grape Red", YEARS, y, b);
	more.show();
	cout << "Total bottles for " << more.Label()
		<< ": " << more.sum() << endl;
	cout << "Bye!";
	return 0;
}