C++ Primer 08 Exercise

01

#include <iostream>

void show(const char * str, int i = 0);

int main()
{
	using namespace std;
	show("abc");
	show("abc");
	show("abc");
	show("abc");
	show("abcde", 1);
	
	return 0;
}

void show(const char * str, int num)
{
	static int count = 0;
	count++;

	if (num == 0)
		std::cout << str << std::endl;
	else
	{
		for(int i = count; i > 0; i--)
			std::cout << str << std::endl;
	}
}

02

#include <iostream>
#include <cstring>

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

void set_candy(CandyBar & candy, const char * str = "Millennium Munch", double w = 2.85, int c = 350);
void Show(const CandyBar & candy);

int main()
{
	using namespace std;
	CandyBar a, b;

	set_candy(a, "aaaaa", 100, 50);
	Show(a);
	set_candy(b);
	Show(b);
	return 0;
}

void set_candy(CandyBar & candy, const char * str, double w, int c)
{
	strcpy(candy.name, str);
	candy.weight = w;
	candy.cal = c;
}

void Show(const CandyBar & candy)
{
	using namespace std;
	cout << "name : " << candy.name << endl;
	cout << "weight : " << candy.weight << endl;
	cout << "cal : " << candy.cal << endl;
}

03

#include <iostream>
#include <string>
using namespace std;

string change_upper(string & str);

int main()
{
	
	
	string str;
	cout << "문자열을 입력하시오 (끝내려면 q) : ";
	getline(cin, str);
	while (str != "q")
	{
		str = change_upper(str);
		cout << str << endl;
		cout << "다음 문자열을 입력하시오 (끝내려면 q) : ";
		getline(cin, str);
	}
	cout << "끝.\n";
	return 0;
}

string change_upper(string &str)
{
	for (int i = 0; str[i]; i++)
		str[i] = toupper(str[i]);
	return str;
}

04

#include <iostream>
#include <cstring>
using namespace std;
struct stringy
{
	char * str;
	int ct;
};

void set(stringy & beany, const char testing[]);
void show(const stringy & beany, int count = 1);
void show(const char testing[], int count = 1);

void show(const stringy & beany, int count)
{
	for (int i = count; i > 0; i--)
		cout << beany.str << endl;
}

void show(const char testing[], int count)
{
	for (int i = count; i > 0; i--)
		cout << testing << endl;
}

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 & beany, const char testing[])
{
	char * new_str = new char;
	beany.str = new_str;
	strcpy(new_str, testing);
	beany.ct = strlen(new_str);
}

05

#include <iostream>

template <class T>
T max5(const T arr[5])
{
	T max;
	max = arr[0];
	for (int i = 1; i < 5; i++)
	{
		if (max < arr[i])
			max = arr[i];
	}
	return max;
}

int main()
{
	using namespace std;

	int arr1[5] = {1, 5, 3, 10, 2};
	double arr2[5] = {1.1, 2.14, 5.42, 3.22, 4.83};

	cout << max5(arr1) << endl;
	cout << max5(arr2) << endl;
	return 0;
}

06

#include <iostream>
#include <cstring>

template <class T>
T maxn(T arr[], int n);

template <>
const char * maxn(const char * arr[], int n);

int main()
{
	using namespace std;

	int arr1[6] = {1, 5, 3, 10, 2, 99};
	double arr2[4] = {1.1, 2.14, 5.42, 3.22};
	const char * arr3[5] = {"a", "bb", "ccc", "dddd", "eeeee"};

	cout << maxn(arr1, 6) << endl;
	cout << maxn(arr2, 4) << endl;
	cout << maxn(arr3, 5) << endl;
	return 0;
}

template <class T>
T maxn(T arr[], int n)
{
	T max;
	max = arr[0];
	for (int i = 1; i < n; i++)
	{
		if (max < arr[i])
			max = arr[i];
	}
	return max;
}

template <>
const char * maxn(const char * arr[], int n)
{
	const char * max = arr[0];
	for (int i = 1; i < n; i++)
	{
		if (strlen(max) < strlen(arr[i]))
			max = arr[i];
	}
	return max;
}

07

#include <iostream>

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

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

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

int main()
{
	using namespace std;
	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 << "Mr.E의 재산의 합 : ";
	cout << SumArray(things, 6) << endl;
	cout << "Mr.E의 채무의 합 : ";
	cout << SumArray(pd, 3) << endl;
	return 0;
}

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

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