《C++ Primer Plus(第六版)》(12)(第八章 函数探幽 编程题答案)

8.8编程练习

1.

void printInfo(char* str, int check = 0)
{
	static int count = 0;
	++count;
	if (check == 0)
	{
		cout << str << endl;
	}
	else
	{
		for (int i = 0; i < count; ++i)
		{
			cout << str << endl;
		}
	}
}
int main()
{
	printInfo("fsdf");
	printInfo("FableGame");
	printInfo("FableGame2",32);
	printInfo("Hello Fable");
	printInfo("Hello Fable333333333333", 5);
	cin.get();
	cin.get();
	return 0;
}
 

2.

struct CandyBar 
{
	string name;
	double weight;
	int energy;
};
void fillCandyBar(CandyBar& cb, const char* name = "Millennium Munch", double weight = 2.85, int energy = 350);
void printInfo(const CandyBar& cb);
int main()
{
	CandyBar cb;
	fillCandyBar(cb);
	printInfo(cb);

	cin.get();
	cin.get();
	return 0;
}

void fillCandyBar(
	CandyBar& cb, 
	const char* name /*= "Millennium Munch"*/, 
	double weight /*= 2.85*/, 
	int energy /*= 350*/)
{
	cb.name = name;
	cb.weight = weight;
	cb.energy = energy;
}

void printInfo(const CandyBar& cb)
{
	cout << "name: " << cb.name << " weight:" << cb.weight << " energy:" << cb.energy;
}

3.

#include 
#include 
#include 
#include 
using namespace std;

void change(string& str)
{
	for (size_t i = 0; i < str.length(); ++i)
	{
		str[i] = toupper(str[i]);
	}
}
int main()
{
	cout << "Enter a string (q to quit): ";
	string str;
	getline(cin, str);
	while (cin && str != "q")
	{
		change(str);
		cout << str << endl;
		cout << "Next string (q to quit): ";
		getline(cin, str);
		
	}
	cout << "Bye." << endl;
	cin.get();
	cin.get();
	return 0;
}

4.

//
//  main.cpp
//  HelloWorld
//  关注微信公众号:传说之路,大家共同学习
//  Created by feiyin001 on 16/4/3.
//  Copyright (c) 2016年 FableGame. All rights reserved.
//

#include 
#include 
using namespace std;
//结构
struct stringy
{
    char * str;
    int ct;
};
//函数声明
void set(stringy& stry, const char* ch);
void show(const stringy& str, int times = 1);
void show(const char* ch, int times = 1);

//main函数
int main(int argc, const char * argv[]) {
    
    stringy beany;
    char testing[] = "Reality isn't what it used to be";
    set(beany, testing);
    show(beany);
    show(beany, 2);
    testing[0] = 'D';
    testing[1] = 'u';
    show(testing);
    show(testing, 3);
    show("Done!");

    return 0;
}
//设置内容
void set(stringy& stry, const char* ch)
{
    stry.ct = (int)strlen(ch);
    stry.str = new char[stry.ct];
    strcpy(stry.str, ch);
    
}
//显示内容
void show(const stringy& str, int times)
{
    for (int i = 0; i < times; ++i) {
        cout << str.str << endl;
    }
}
//显示字符串
void show(const char* ch, int times)
{
    for (int i = 0; i < times; ++i) {
        cout << ch << endl;
    }
}

5.

template 
T max5(T* a);
int main()
{
	int a[5] = { 1, 2, 3, 4, 5 };
	double b[] = { 23.32, 323, 22, 353.3, 323.3, 99999 };

	cout << max5(a) << endl;
	cout << max5(b) << endl;

	std::cin.get();
	std::cin.get();
	return 0;
}
template
T max5(T* a)
{
	T b = a[0];
	for (int i = 1; i < 5; ++i)
	{
		if ( b < a[i])
		{
			b = a[i];
		}
	}
	return b;
}

6.

template 
T maxn(T a[], int num);
template<> char* maxn(char* a[], int num);

int main()
{
	int a[6] = { 1, 2, 3, 4, 5, 6 };
	double b[4] = { 23.32, 323, 22, 353.3 };

	cout << maxn(a, 6) << endl;
	cout << maxn(b, 4) << endl;
	char* c[5] = { "abc", "fable game", "FableGame", "C++", "凡人修真3D" };
	cout << maxn(c, 5) << endl;
	std::cin.get();
	std::cin.get();
	return 0;
}
template
T maxn(T a[], int num)
{
	T b = a[0];
	for (int i = 1; i < num; ++i)
	{
		if ( b < a[i])
		{
			b = a[i];
		}
	}
	return b;
}
template<>
char* maxn(char* a[], int num)
{
	size_t len = strlen(a[0]);
	char* ch = a[0];
	for (int i = 1; i < num; ++i)
	{
		if (len < strlen(a[i]))
		{
			ch = a[i];
		}
	}
	return ch;
}

7.

修改前:

#include 
#include 
#include 
#include 
using namespace std;

template
void ShowArray(T arr[], int n);
template
void ShowArray(T* arr[], int n);
struct debts 
{
	char name[50];
	double amount;
};
int main()
{
	int things[6] = { 13, 31, 103, 301, 310, 130 };
	struct debts mr_E[3] =
	{
		{ "Ima Wolfe", 2400.0 },
		{ "Ura Foxe", 1300.0 },
		{ "Iby Stout", 1800.0 }
	};
	double * pd[3];
	for (int i = 0; i < 3; i++)
	{
		pd[i] = &mr_E[i].amount;
	}
	cout << "Listing Mr. E's counts of things:\n";
	ShowArray(things, 6);
	cout << "Listing Mr. E's debts:\n";
	ShowArray(pd, 3);
	std::cin.get();
	std::cin.get();
	return 0;
}
template
void ShowArray(T arr[], int n)
{
	cout << "template A\n";
	for (int i = 0; i < n; i++)
	{
		cout << arr[i] << ' ';
	}
	cout << endl;
}
template
void ShowArray(T* arr[], int n)
{
	cout << "template B\n";
	for (int i = 0; i < n; i++)
	{
		cout << *arr[i] << ' ';
	}
	cout << endl;
}

修改后:

#include 
#include 
#include 
#include 
using namespace std;

template
void ShowArray(T arr[], int n);
template
void ShowArray(T* arr[], int n);
template
T SumArray(T arr[], int n);
template
T SumArray(T* arr[], int n);
struct debts 
{
	char name[50];
	double amount;
};
int main()
{
	int things[6] = { 13, 31, 103, 301, 310, 130 };
	struct debts mr_E[3] =
	{
		{ "Ima Wolfe", 2400.0 },
		{ "Ura Foxe", 1300.0 },
		{ "Iby Stout", 1800.0 }
	};
	double * pd[3];
	for (int i = 0; i < 3; i++)
	{
		pd[i] = &mr_E[i].amount;
	}
	cout << "Listing Mr. E's counts of things:\n";
	ShowArray(things, 6);
	cout << "sum: " << SumArray(things, 6) << endl;
	cout << "Listing Mr. E's debts:\n";
	ShowArray(pd, 3);
	cout << "sum: " << SumArray(pd, 3) << endl;
	std::cin.get();
	std::cin.get();
	return 0;
}
template
void ShowArray(T arr[], int n)
{
	cout << "template A\n";
	for (int i = 0; i < n; i++)
	{
		cout << arr[i] << ' ';
	}
	cout << endl;
}
template
void ShowArray(T* arr[], int n)
{
	cout << "template B\n";
	for (int i = 0; i < n; i++)
	{
		cout << *arr[i] << ' ';
	}
	cout << endl;
}
template
T SumArray(T arr[], int n)
{
	T sum = 0;
	for (int i = 0; i < n; i++)
	{
		sum += arr[i];
	}
	return sum;
}
template
T SumArray(T* arr[], int n)
{
	T sum = 0;
	for (int i = 0; i < n; i++)
	{
		sum += *arr[i];
	}
	return sum;
}












转载于:https://www.cnblogs.com/fablegame/p/6430253.html

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