C++Primer Plus（第六版）第十四章第一题

最新推荐文章于 2024-08-25 10:39:26 发布

greatlisten

最新推荐文章于 2024-08-25 10:39:26 发布

阅读量291

点赞数

CC 4.0 BY-SA版权

分类专栏： C++ Primer Plus（第六版）文章标签： C++Primer Plus

本文链接：https://blog.youkuaiyun.com/greatlisten/article/details/77413009

C++ Primer Plus（第六版）专栏收录该内容

16 篇文章

订阅专栏

本文介绍了一个模板类Pair及其使用示例，并通过Wine类展示了如何利用Pair类来管理不同年份的酒类库存信息。文章还提供了一个完整的C++程序，包括类定义、成员函数实现及主函数，用于演示如何输入和显示数据。

PS：之前文章标题只知道复制之前文章，忘记改名字了，不好意思

这题比较简单，Pair类是个模板类，也需要实例化

winec.h

// winec.h
#ifndef WINEC_H_
#define WINEC_H_
#include <iostream>
#include <string>
#include <valarray>
template<typename T1, typename T2>
class Pair
{
private:
	T1 year;
	T2 bottles;
public:
	Pair(const T1 & yr, const T2 & bt) :year(yr), bottles(bt) {}
	Pair() {}
	void Set(const T1 & yr, const T2 & bt);
	int Sum() const;
	void Show(int y) const;
};

template<typename T1, typename T2>
void Pair<T1, T2>::Set(const T1 & yr, const T2 & bt)
{
	year = yr;
	bottles = bt;
}

template<typename T1, typename T2>
inline int Pair<T1, T2>::Sum() const
{
	return bottles.sum();
}

template<typename T1, typename T2>
inline void Pair<T1, T2>::Show(int y) const
{
	for (int i = 0; i < y; i++)
		std::cout << "\t" << year[i] << "\t" << bottles[i] << std::endl;
}

class Wine
{
private:
	typedef std::valarray<int> ArrayInt;
	typedef Pair<ArrayInt, ArrayInt> PairArray;
	std::string label;
	PairArray yb;
	int yrs;
public:
	// initialize label to l, number of years to y,
	// vintage years to yr[], bottles to bot[]
	Wine(const char * l, int y, const int yr[], const int bot[]);
	// initialize label to l, number of years to y,
	// create array objects of length y
	Wine(const char * l, int y);
	void GetBottles();
	std::string & Label();
	void Show() const;
	int Sum() const;
};
#endif // !WINEC_H_

winec.cpp

#include "winec.h"
#include <iostream>

// winec.cpp

Wine::Wine(const char * l, int y, const int yr[], const int bot[])
{
	label = l;
	yrs = y;
	yb.Set(ArrayInt(yr, yrs), ArrayInt(bot, yrs));
}

Wine::Wine(const char * l, int y)
{
	label = l;
	yrs = y;
}

void Wine::GetBottles()
{
	ArrayInt yr(yrs), bt(yrs);
	std::cout << "Enter " << label << " data for " << yrs << " year(s):\n";
	for (int i = 0; i < yrs; i++)
	{
		std::cout << "Enter year: ";
		std::cin >> yr[i];
		std::cout << "Enter bottles for that year: ";
		std::cin >> bt[i];
	}
	while (std::cin.get() != '\n')
		continue;
	yb.Set(yr, bt);
}

std::string & Wine::Label()
{
	return label;
}

void Wine::Show() const
{
	std::cout << "Wine: " << label << std::endl;
	std::cout << "\tYear\tBottles\n";
	yb.Show(yrs);
}

int Wine::Sum() const
{
	return yb.Sum();
}

main.cpp

// pe14-1.cpp -- using Wine class with cintainment
#include <iostream>
#include "winec.h"

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

	cout << "Enter name of wine: ";
	char lab[50];
	cin.getline(lab, 50);
	cout << "Enter number of years: ";
	int yrs;
	cin >> yrs;

	Wine holding(lab, yrs); // store label, years, give arrays yrs elements
	holding.GetBottles(); // solicit input for year, bottle count
	holding.Show(); // display object contents

	const int YRS = 3;
	int y[YRS] = { 1993,1995,1998 };
	int b[YRS] = { 48,60,72 };
	// create new object, initialize using data in arrays y and b
	Wine more("Gushing Grape Red", YRS, y, b);
	more.Show();
	cout << "Total bottles for " << more.Label() // use Label() method
		<< ": " << more.Sum() << endl;
	cout << "Bye\n";
	cin.get();
	return 0;
}