[C++] 명품 C++ 프로그래밍 7장

실습문제

1번

(1)

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

class Book {
    string title;
    int money, page;
public:
    Book(string title = "", int money = 0, int page = 0) {
        this->title = title;
        this->money = money;
        this->page = page;
    }
    Book operator+=(int x) {
        money += x;
        return *this;
    }
    Book operator-=(int x) {
        money -= x;
        return *this;
    }

    void show() {
        cout << title << " " << money << "원 " << page << " 페이지" << endl;
    }
};

int main() {
    Book a("청춘", 20000, 300), b("미래", 30000, 500);
    a += 500;
    b -= 500;
    a.show();
    b.show();
}

(2)

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

class Book {
    string title;
    int money, page;
public:
    Book(string title = "", int money = 0, int page = 0) {
        this->title = title;
        this->money = money;
        this->page = page;
    }
    friend void operator+=(Book &book, int x);
    friend void operator-=(Book& book, int x);


    void show() {
        cout << title << " " << money << "원 " << page << " 페이지" << endl;
    }
};
void operator+=(Book& book, int x) {
    book.money += x;
}
void operator-=(Book& book, int x) {
    book.money -= x;
}

int main() {
    Book a("청춘", 20000, 300), b("미래", 30000, 500);
    a += 500;
    b -= 500;
    a.show();
    b.show();
}

1번

 

2번

(1)

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

class Book {
    string title;
    int money, page;
public:
    Book(string title = "", int money = 0, int page = 0) {
        this->title = title;
        this->money = money;
        this->page = page;
    }
    bool operator==(int x) {
        if (money == x)
            return true;
        return false;
    }
    bool operator==(string x) {
        if (title.compare(x) == 0)
            return true;
        return false;
    }
    bool operator==(Book x) {
        if (title == x.title && money == x.money && x.page == page) {
            return true;
        }
        return false;
        return false;
    }


    void show() {
        cout << title << " " << money << "원 " << page << " 페이지" << endl;
    }
};


int main() {
    Book a("명품 C++", 30000, 500), b("고품 C++", 30000, 500);
    if (a == 30000) cout << "정가 30000원" << endl;
    if (a == "명품 C++") cout << "명품 C++ 입니다." << endl;
    if (a == b) cout << "두 책이 같은 책입니다." << endl;
}

(2)

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

class Book {
    string title;
    int money, page;
public:
    Book(string title = "", int money = 0, int page = 0) {
        this->title = title;
        this->money = money;
        this->page = page;
    }
    friend bool operator==(Book& book, int x);
    friend bool operator==(Book& book, string x);
    friend bool operator==(Book& book, Book x);


    void show() {
        cout << title << " " << money << "원 " << page << " 페이지" << endl;
    }
};
bool operator==(Book& book, int x) {
    if (book.money == x)
        return true;
    return false;
}
bool operator==(Book& book, string x) {
    if (book.title.compare(x) == 0)
        return true;
    return false;
}
bool operator==(Book& book, Book x) {
    if (book.title == x.title && book.money == x.money && x.page == book.page) {
        return true;
    }
    return false;
}

int main() {
    Book a("명품 C++", 30000, 500), b("고품 C++", 30000, 500);
    if (a == 30000) cout << "정가 30000원" << endl;
    if (a == "명품 C++") cout << "명품 C++ 입니다." << endl;
    if (a == b) cout << "두 책이 같은 책입니다." << endl;
}

2번

 

3번

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

class Book {
	string name;
	int price, pages;
public:
	Book(string name = "", int price = 0, int pages = 0) {
		this->name = name;
		this->price = price;
		this->pages = pages;
	}

	bool operator !() {
		if (price == 0)
			return true;
		return false;
	}
};

int main() {
	Book book("벼룩시장", 0, 50);
	if (!book) cout << "공짜다" << endl;
}

3번

 

4번

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

class Book {
    string title;
    int money, page;
public:
    Book(string title = "", int money = 0, int page = 0) {
        this->title = title;
        this->money = money;
        this->page = page;
    }

    string getTitle() {
        return title;
    }
    friend bool operator <(Book a, Book b);
    
};
bool operator <(Book a, Book b) {
    if (a.getTitle() < b.getTitle()) {
        return true;
    }
    return false;
}
int main() {
    Book a("청춘", 20000, 300);
    string b;
    cout << "책 이름을 입력하세요>> ";
    getline(cin, b);
    if (b < a) {
        cout << a.getTitle() << "이 " << b << "보다 뒤에 있구나!" << endl;
    }
}

4번

 

5번

(1)

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

class Color {
    int r, g, b;
public:
    Color(int r = 0, int g = 0, int b = 0) {
        this->r = r;
        this->g = g;
        this->b = b;
    }

    Color operator+ (Color op) {
;
        r = r + op.r;
        b = b + op.b;
        g = g + op.g;
        return *this;
    }

    bool operator == (Color op) {
        if (r == op.r && g == op.g && b == op.b)
            return true;
        return false;
    }

    void show() {
        cout << r << " " << g << " " << b << endl;
    }
    
};

int main() {
    Color red(255, 0, 0), blue(0, 0, 255), c;
    c = red + blue;
    c.show();

    Color fuchsia(255, 0, 255);
    if (c == fuchsia)
        cout << "보라색 맞음";
    else
        cout << "보라색 아님";
}

 

(2)

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

class Color {
    int r, g, b;
public:
    Color(int r = 0, int g = 0, int b = 0) {
        this->r = r;
        this->g = g;
        this->b = b;
    }
    friend Color operator+ (Color op1, Color& op2);
    friend bool operator == (Color op1, Color op2);
    

    void show() {
        cout << r << " " << g << " " << b << endl;
    }
    
};

Color operator+ (Color op1, Color &op2) {
    op2.r = op1.r + op2.r;
    op2.b = op1.b + op2.b;
    op2.g = op1.g + op2.g;
    return op2;
}

bool operator == (Color op1, Color op2) {
    if (op2.r == op1.r && op2.g == op1.g && op2.b == op1.b)
        return true;
    return false;
}

int main() {
    Color red(255, 0, 0), blue(0, 0, 255), c;
    c = red + blue;
    c.show();

    Color fuchsia(255, 0, 255);
    if (c == fuchsia)
        cout << "보라색 맞음";
    else
        cout << "보라색 아님";
}

5번

 

6번

(1)

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

class Matrix {
	int arr[4];
public:
	Matrix(int arr1 = 0, int arr2 = 0, int arr3 = 0, int arr4 = 0) {
		arr[0] = arr1;
		arr[1] = arr2;
		arr[2] = arr3;
		arr[3] = arr4;
	}
	Matrix operator +(Matrix op) {
		Matrix tmpMatrix;
		for (int i = 0; i < 4; i++) {
			tmpMatrix.arr[i] = arr[i] + op.arr[i];
		}
		return tmpMatrix;
	}
	void operator += (Matrix op) {
		for (int i = 0; i < 4; i++) {
			arr[i] += op.arr[i];
		}
	}
	bool operator == (Matrix op) {
		for (int i = 0; i < 4; i++) {
			if (arr[i] != op.arr[i]) return false;
		}
		return true;
	}
	void show() {
		cout << "Matrix = {";
		for (int i = 0; i < 4; i++) cout << arr[i] << ' ';
		cout << "}" << endl;
	}
};


int main() {
	Matrix a(1, 2, 3, 4), b(2, 3, 4, 5), c;
	c = a + b;
	a += b;
	a.show();
	b.show();
	c.show();
	if (a == c)
		cout << "a and c are the same" << endl;
}

 

(2)

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

class Matrix {
	int arr[4];
public:
	Matrix(int arr1 = 0, int arr2 = 0, int arr3 = 0, int arr4 = 0) {
		arr[0] = arr1;
		arr[1] = arr2;
		arr[2] = arr3;
		arr[3] = arr4;
	}
	friend Matrix operator +(Matrix op1, Matrix op2);
	friend void operator += (Matrix &op1, Matrix op2);
	friend bool operator == (Matrix op1, Matrix op2);
	void show() {
		cout << "Matrix = {";
		for (int i = 0; i < 4; i++) cout << arr[i] << ' ';
		cout << "}" << endl;
	}
};
Matrix operator +(Matrix op1, Matrix op2) {
	Matrix tmpMatrix;
	for (int i = 0; i < 4; i++) {
		tmpMatrix.arr[i] = op1.arr[i] + op2.arr[i];
	}
	return tmpMatrix;
}
void operator += (Matrix &op1, Matrix op2) {
	for (int i = 0; i < 4; i++) {
		op1.arr[i] += op2.arr[i];
	}
}
bool operator == (Matrix op1, Matrix op2) {
	for (int i = 0; i < 4; i++) {
		if (op2.arr[i] != op1.arr[i]) return false;
	}
	return true;
}


int main() {
	Matrix a(1, 2, 3, 4), b(2, 3, 4, 5), c;
	c = a + b;
	a += b;
	a.show();
	b.show();
	c.show();
	if (a == c)
		cout << "a and c are the same" << endl;
}

6번

 

7번

(1)

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

class Matrix {
	int arr[4];
public:
	Matrix(int arr1 = 0, int arr2 = 0, int arr3 = 0, int arr4 = 0) {
		arr[0] = arr1;
		arr[1] = arr2;
		arr[2] = arr3;
		arr[3] = arr4;
	}
	
	void operator >> (int *arrs) {
		for (int i = 0; i < 4; i++) {
			arrs[i] = arr[i];
		}
	}
	void operator << (int *arrs) {
		for (int i = 0; i < 4; i++) {
			arr[i] = arrs[i];
		}
	}

	void show() {
		cout << "Matrix = {";
		for (int i = 0; i < 4; i++) cout << arr[i] << ' ';
		cout << "}" << endl;
	}
};



int main() {
	Matrix a(4, 3, 2, 1), b;
	int x[4], y[4] = { 1,2,3,4 };
	a >> x;
	b << y;

	for (int i = 0; i < 4; i++) cout << x[i] << ' ';
	cout << endl;
	b.show();
}

 

(2)

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

class Matrix {
	int arr[4];
public:
	Matrix(int arr1 = 0, int arr2 = 0, int arr3 = 0, int arr4 = 0) {
		arr[0] = arr1;
		arr[1] = arr2;
		arr[2] = arr3;
		arr[3] = arr4;
	}
	friend void operator >> (Matrix op, int* arrs);
	friend void operator << (Matrix &op, int* arrs);


	void show() {
		cout << "Matrix = {";
		for (int i = 0; i < 4; i++) cout << arr[i] << ' ';
		cout << "}" << endl;
	}
};
void operator >> (Matrix op, int* arrs) {
	for (int i = 0; i < 4; i++) {
		arrs[i] = op.arr[i];
	}
}
void operator << (Matrix &op, int* arrs) {
	for (int i = 0; i < 4; i++) {
		op.arr[i] = arrs[i];
	}
}


int main() {
	Matrix a(4, 3, 2, 1), b;
	int x[4], y[4] = { 1,2,3,4 };
	a >> x;
	b << y;

	for (int i = 0; i < 4; i++) cout << x[i] << ' ';
	cout << endl;
	b.show();
}

7번

 

8번

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

class Circle {
	int radius;
public:
	Circle(int radius = 0) { this->radius = radius; }
	void show() { cout << "radius = " << radius << "인 원" << endl;}
	friend void operator ++(Circle &r);
	friend Circle operator ++(Circle &r, int x);
};

void operator ++(Circle &r) {
	r.radius += 1;
}

Circle operator ++(Circle &r, int x) {
	Circle tempCircle = r;
	r.radius += 1;
	return tempCircle;
}


int main() {
	Circle a(5), b(4);
	++a;
	b = a++;
	a.show();
	b.show();
}

8번

 

9번

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

class Circle {
	int radius;
public:
	Circle(int radius = 0) { this->radius = radius; }
	void show() { cout << "radius = " << radius << "인 원" << endl;}
	
	friend Circle operator +(int x, Circle op);
};

Circle operator +(int x, Circle op) {
	op.radius += x;
	return op;
}


int main() {
	Circle a(5), b(4);
	b = 1 + a;
	a.show();
	b.show();
}

9번

 

10번

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

class Statistics {
    int *arr;
    int size;
    int max;
public:
    Statistics(int max = 10) {
        size = 0;
        arr = new int[max];
    }

    bool operator!() {
        if (size == 0) return true;
        else false;
    }

    void operator~() {
        for (int i = 0; i < size; i++) {
            if (arr[i] != NULL) {
                cout << arr[i] << ' ';
            }
        }
        cout << endl;
    }
    void operator >> (int& a) {
        int sum = 0;
        for (int i = 0; i < size; i++) sum += arr[i];
        a = sum / size;
    }
    Statistics& operator << (int b) {
        arr[size] = b;
        size++;
        return *this;
    }
    ~Statistics() { delete[] arr; }
};




int main() {
    Statistics stat;
    if (!stat) cout << "현재 통계 데이타가 없습니다." << endl;

    int x[5];
    cout << "5 개의 정수를 입력하라>>";
    for (int i = 0; i < 5; i++) cin >> x[i];

    for (int i = 0; i < 5; i++) stat << x[i];
    stat << 100 << 200;
    ~stat;

    int avg;
    stat >> avg;
    cout << "avg=" << avg << endl;
}

10번

 

11번

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

class Stack {
    int arr[10];
    int idx;
public:
    Stack() { for (int i = 0; i < 10; i++) arr[i] = 0; idx = 0; }
    
    Stack& operator << (int n) {
        arr[idx++] = n;
        return *this;
    }
    bool operator !() {
        if (idx <= 0) return true;
        return false;
    }
    void operator >>(int& n) {
        n = arr[idx - 1];
        idx--;
    }
};

int main() {
    Stack stack;
    stack << 3 << 5 << 10;
    while (true) {
        if (!stack) break;
        int x;
        stack >> x;
        cout << x << ' ';
    }
    cout << endl;
}

11번

 

12번

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

class SortedArray {
    int size;
    int* p;
    void sort();
public:
    SortedArray();
    SortedArray(SortedArray& src);
    SortedArray(int p[], int size);
    ~SortedArray();
    SortedArray operator+(SortedArray& op2);
    SortedArray& operator=(const SortedArray& op2);
    void show();
};

void SortedArray::sort() {
    int temp;
    for (int i = 0; i < size; i++) {
        for (int j = 0; j < size - 1; j++) {
            if (p[j] > p[j + 1]) {
                temp = p[j];
                p[j] = p[j + 1];
                p[j + 1] = temp;
            }
        }
    }
}

SortedArray::SortedArray() {
    p = nullptr;
    size = 0;
}

SortedArray::SortedArray(SortedArray& src) {
    this->size = src.size;
    this->p = new int[src.size];
    for (int i = 0; i < src.size; i++)
        this->p[i] = src.p[i];
}

SortedArray::SortedArray(int p[], int size) {
    this->size = size;
    this->p = new int[size];
    for (int i = 0; i < size; i++)
        this->p[i] = p[i];
}

SortedArray::~SortedArray() {
    delete[] p;
}

SortedArray SortedArray::operator+(SortedArray& op2) {
    SortedArray tempArray;
    tempArray.p = new int[this->size + op2.size];
    for (int i = 0; i < this->size; i++)
        tempArray.p[tempArray.size++] = this->p[i];
    for (int i = 0; i < op2.size; i++)
        tempArray.p[tempArray.size++] = op2.p[i];
    return tempArray;
}

SortedArray& SortedArray::operator= (const SortedArray& op2) {
    delete[] p;
    this->size = op2.size;
    this->p = new int[this->size];
    for (int i = 0; i < this->size; i++) {
        this->p[i] = op2.p[i];
    }
    return *this;
}


void SortedArray::show() {
    sort();	
    cout << "배열 출력 : ";
    for (int i = 0; i < size; i++)		
        cout << p[i] << ' ';	
    cout << endl;

}

int main() {
    int n[] = { 2, 20, 6 };
    int m[] = { 10, 7, 8, 30 };
    SortedArray a(n, 3), b(m, 4), c;

    c = a + b;

    a.show();
    b.show();
    c.show();
}

12번