(C++기초플러스 6판 프로그래밍 연습 정답,솔루션) CHAPTER 07 함수-C++의 프로그래밍 모듈 p.461~ 1번~6번

1번

#include<iostream>
double aver(double x, double y);
int main()
{
	using namespace std;
	double x, y,z;
	for(;;)
	{
		cout << "두 수 입력: ";
		cin >> x >> y;
		if (x == 0 || y == 0)
			break;
		z = aver(x, y);
		cout << "조화평균 = " << z << endl;
	}

	return 0;
}
double aver(double x, double y)
{
	return 2.0 * x * y / (x + y);
}

 

 

2번

#include<iostream>
using namespace std;
int input(double score[], int n);
void output(const double score[], int n,double aver);
double aver_cum(const double score[], int n);
int main()
{
	cout << "골프 스코어 입력 (숫자를 제외한 문자 입력시 종료)\n";
	double score[10],aver;
	int n;
	n=input(score, 10);
	aver = aver_cum(score, n);
	output(score, n, aver);

	return 0;
}
int input(double score[], int n)
{
	for (int i = 0; i < 10; i++)
	{
		cout << i + 1 << "번째: ";
		if (!(cin >> score[i]))
		{
			n = i;
			break;
		}
	}
	return n;
}

double aver_cum(const double score[], int n)
{
	double sum=0.0;
	for (int i = 0; i < n; i++)
		sum += score[i];
	return sum / n;
}

void output(const double score[], int n, double aver)
{
	for (int i = 0; i < n; i++)
		cout << i + 1 << "번: " << score[i] << " ";
	cout << "\n평균 스코어 : " << aver;
}

 

3번

#include<iostream>
using namespace std;
struct box
{
	char maker[40];
	float height;
	float width;
	float length;
	float volume;
};

void output(struct box);
void set_vol(struct box *);

int main()
{
	struct box a = {
		"abc",10,20,3,600
	};
	output(a);

	struct box b;
	cout << "maker: "; 	cin >> b.maker;
	cout << "height: "; 	cin >> b.height;
	cout << "width: "; 	cin >> b.width;
	cout << "length: "; 	cin >> b.length;

	set_vol(&b);
	output(b);
}

 

4번

#include<iostream>
long double probability(unsigned numbers, unsigned picks,unsigned mega);
int main()
{
	using namespace std;
	double total, choices, mega;
	cout << "전체 수의 개수와 뽑을 수의 개수를 입력하십시오:\n";
	while ((cin >> total >> choices) && choices <= total)
	{
		cout << "두 번째 범위를 입력하십시오:\n";
		cin >> mega;
		cout << "당신이 이길 확률은 ";
		cout << probability(total, choices, mega);
		cout << "번 중에서 한 번 입니다.\n";
		cout << "다시 두 수를 입력하십시오. (끝내려면 q를 입력): ";
	}
	cout << "프로그램 종료.\n";
	return 0;
}

 

5번

#include<iostream>
int fact(int n);
int main()
{
	for (;;)
	{
		std::cout << "계승 입력: ";
		int n;
		if (!(std::cin >> n))
			break;
		 std::cout<<n<<"! = "<<fact(n)<<std::endl;
	}
	return 0;
}
int fact(int n)
{
	if (n > 0)
		return n * fact(n - 1);
	else
		return 1;
}

long double probability(unsigned numbers, unsigned picks, unsigned mega)
{
	long double result = 1.0;
	long double n;
	unsigned p;

	for (n = numbers, p = picks; p > 0; n--, p--)
		result = result * n / p;
	return result * mega;
}


void output(struct box a)
{
	cout << a.maker << " " << a.height << " " << a.width
		<< " " << a.length << " " << a.volume << endl;
}

void set_vol(struct box* b)
{
	b->volume = b->height * b->width * b->length;
}

 

6번

#include<iostream>
int Fill_array(double ar[], int n);
void Show_array(const double ar[], int n);
void Reverse_array(double ar[], int n);

using namespace std;

int main()
{
	double ar[10];
	int n = Fill_array(ar, 5);
	Show_array(ar, n);
	cout << "REVERSE" << endl;
	Reverse_array(ar + 1, n - 2);
	Show_array(ar, n);
}
int Fill_array(double ar[], int n)
{
	int i = 0;
	for (; i < n; i++)
	{
		cout << i + 1 << "번째 double 값 : ";
		if (!(cin >> ar[i]))
			break;
	}
	return i;
}

void Show_array(const double ar[], int n)
{
	for (int i = 0; i < n; i++)
		cout << i + 1 << " : " << ar[i] << endl;
}

void Reverse_array(double ar[], int n)
{
	for (int i = 0; i < n / 2; i++)
	{
		int temp;
		temp = ar[i];
		ar[i] = ar[n - i - 1];
		ar[n - i - 1] = temp;
	}
}