C++ Primer Plus第六版 第八章 编程练习答案

23333 时隔一年我来填坑了 CPP继续往后读然后把题目写了_(:з」∠)_ 写到哪更到哪 不一次性更完了

//第一题
#include <iostream>

void PrintStr(char *str, int flag = 0);

int main()
{
	char str[] = "fuck fuck fuck";
	std::cout << "#1 " << std::endl;
	PrintStr(str);
	std::cout << "#2 " << std::endl;
	PrintStr(str, 1996);
	std::cout << "#3 " << std::endl;
	PrintStr(str, 1996);
	std::cout << "#4 " << std::endl;
	PrintStr(str);
	return 0;
}

void PrintStr(char *str, int flag)
{
	static int count = 0;
	++count;
	if(!flag)
		std::cout << str << std::endl;
	else
		for(int i = 0 ; i < count ; ++i)
			std::cout << str << std::endl;
}

//第二题
#include <iostream>
#include <cstring>

struct CandyBar{
	char name[30];
	double weight;
	int heat;
};

void setCandyBar(CandyBar &c, const char *s = "Millennium Munch", const double w = 2.85, const int h = 350);
void disp(const CandyBar &c);

int main()
{
	CandyBar c;
	setCandyBar(c);
	disp(c);
	char name[30];
	double weight;
	int heat;
	std::cin.getline(name, 30);
	std::cin >> weight >> heat;
	setCandyBar(c, name, weight, heat);
	disp(c);
	return 0;
}

void setCandyBar(CandyBar &c, const char *s, const double w, const int h)
{
	strcpy(c.name, s);
	c.weight = w;
	c.heat = h;
}

void disp(const CandyBar &c)
{
	std::cout << c.name << std::endl << c.weight << std::endl << c.heat << std::endl;
}

//第三题
#include <iostream>
#include <string>

void changeUpper(std::string &s);

int main()
{
	std::string s;
	while(getline(std::cin, s) && s[0] != 'q')
	{
		changeUpper(s);
		std::cout << s << std::endl;
	}
	return 0;
}

void changeUpper(std::string &s)
{
	for(int i = 0; i < s.size(); ++i)
		s[i] = toupper(s[i]);
}

//第四题
#include <iostream>
#include <cstring>

struct stringy{
	char *str;
	int ct;
};

void set(stringy &s, const char *str);
void show(const char *str, const int count = 1);
void show(const stringy &s, const int count = 1);

int main()
{
	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;
}

void set(stringy &s, const char *str)
{
	int len = strlen(str);
	s.ct = len;
	s.str = new char(len + 1); //要留一个字符存放'\0' 所以分配len + 1空间
	strcpy(s.str, str);
}

void show(const char *str, const int count)
{
	for(int i = 0 ; i < count ; ++i)
		std::cout << str << std::endl;
}

void show(const stringy &s, const int count)
{
	for(int i = 0 ;i < count ; ++i)
		std::cout << s.str << std::endl;
}

//第五题
#include <iostream>

template <typename T>
T max5(T *a);

int main()
{
	int a[5] = {2, 3, 1, 5, 4};
	double b[5] = {1.1, 3.3, 5.5, 4.4, 2.2};
	std::cout << max5(a) << std::endl;
	std::cout << max5(b) << std::endl;
	return 0;
}

template <typename T>
T max5(T *a)
{
	T max = -1;
	for(int i = 0 ;i < 5 ; ++i)
		max = max < a[i] ? a[i] : max;
	return max;
}

//第六题
#include <iostream>
#include <cstring>

template <typename T>
T maxn(T *a, int len);

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

int main()
{
	int a[6] = {1, 2, 3, 4, 5, 6};
	double b[4] = {1.1, 2.2, 3.3, 4.4};
	char *c[5] = {"fuck", "fuckfuck", "fuckfuckfuck", "fuckfuckfuckfuck", "fuckfuckfuckfuckfuck"};
	std::cout << maxn(a, 6) << std::endl;
	std::cout << maxn(b, 4) << std::endl;
	std::cout << maxn(c, 5) << std::endl;
	return 0;
}

template <typename T>
T maxn(T *a, int len)
{
	T max = -1;
	for(int i = 0 ; i < len ; ++i)
		max = max < a[i] ? a[i] : max;
	return max;
}

template <> char *maxn(char *a[], int len)
{
	int max = -1;
	char *p = NULL;
	for(int i = 0 ; i < len ; ++i)
	{
		if((int)strlen(a[i])> max)
		{
			max = strlen(a[i]);
			p = a[i];
		}
	}
	return p;
}

//第七题
#include <iostream>

struct debts
{
	char name[50];
	double amount;
};

template <typename T>
T SumArray(T a[], int n);

template <typename T>
T SumArray(T *a[], int n);

int main()
{
	int things[6] = {13, 31, 103, 301, 310, 130};
	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;
	std::cout << SumArray(things, 6) << std::endl;
	std::cout << SumArray(pd, 3) << std::endl;
	return 0;
}

template <typename T>
T SumArray(T a[], int n)
{
	T sum = 0 ;
	for(int i = 0 ; i < n ; ++i)
		sum += a[i];
	return sum;
}

template <typename T>
T SumArray(T *a[], int n)
{
	T sum = 0;
	for(int i = 0 ; i < n ; ++i)
		sum += *a[i];
	return sum;
}