[명품 C++ Programming] 5장 실습 문제

1.

#include <iostream>
using namespace std;

class Circle
{
    int radius;
public:
    Circle() { radius = 1; }
    Circle(int radius) { this->radius = radius; }
    int getRadius() { return radius; }
    void setRadius(int radius) { this->radius = radius; }
};

void swap(Circle& a, Circle& b) {
    int temp = a.getRadius();
    a.setRadius(b.getRadius());
    b.setRadius(temp);
}

int main()
{
    Circle a(10);
    Circle b(20);
    cout << "a의 반지름 >> " << a.getRadius() << endl;
    cout << "b의 반지름 >> " << b.getRadius() << endl;
    swap(a, b);
    cout << "a의 반지름 >> " << a.getRadius() << endl;
    cout << "b의 반지름 >> " << b.getRadius() << endl;
}

---

2.

#include <iostream>
using namespace std;

void half(double& a) {
	a /= 2;
}

int main() {
	double n = 20;
	half(n);
	cout << n;
}

---

3.

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


void combine(string t1, string t2, string& t3) {
	t3 = t1 + " " + t2;
}

int main() {
	string text1("I love you"), text2("very much");
	string text3;
	combine(text1, text2, text3);
	cout << text3;
}

---

4. 

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


bool bigger(int a, int b, int& big) {
	big = (a > b) ? a : b;
	return a == b ? true : false;
}

int main() {
	int a, b, big;
	cin >> a >> b;

	if (bigger(a, b, big))
		cout << "두 수는 같습니다." << endl;
	else
		cout << "두 수는 다릅니다." << endl;
	cout << "더 큰 수는 " << big << "입니다." << endl;
}

---

5.

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

class Circle {
	int radius;
public:
	Circle(int r) { radius = r; }
	int getRadius() { return radius; }
	void setRadius(int r) { radius = r; }
	void show() { cout << "반지름이 " << radius << "인 원" << endl; }
};

void increaseBy(Circle& a, Circle& b) {
	a.setRadius(a.getRadius() + b.getRadius());
}

int main() {
	Circle x(10), y(5);
	increaseBy(x, y);
	x.show();
}

---

6.

#include <iostream>
using namespace std;

char& find(char a[], char c, bool& success) {
	for (int i = 0; a[i] != '\0'; i++) {
		if (a[i] == c) {
			success = true;
			return a[i];
		}
	}
	success = false;
}

int main() {
	char s[] = "Mike";
	bool b = false;
	char& loc = find(s, 'M', b);

	if (b == false) {
		cout << "M을 발견할 수 없다" << endl;
		return 0;
	}
	loc = 'm';
	cout << s << endl;

}

---

7.

#include <iostream>
using namespace std;

class MyIntStack {
	int p[10];
	int tos;
public:
	MyIntStack();
	bool push(int n);
	bool pop(int& n);
};

MyIntStack::MyIntStack() {
	tos = -1;
}

bool MyIntStack::push(int n) {
	if (tos == 10 - 1)  // (tos == sizeof(p)/sizeof(p[0]) -1) 도 가능하다
		return false;
	else {
		p[++tos] = n;
		return true;
	}
}

bool MyIntStack::pop(int& n) {
	if (tos == -1) 
		return false;
	else {
		n = p[tos--];
		return true;
	}
}
 
int main() {
	MyIntStack a;
	for (int i = 0; i < 11; i++) {
		if (a.push(i)) cout << i << ' ';
		else cout << endl << i + 1 << " 번째 stack full" << endl;
	}
	int n;
	for (int i = 0; i < 11; i++) {
		if (a.pop(n)) cout << n << ' ';
		else cout << endl << i + 1 << " 번째 stack emtpy";
	}
	cout << endl;
}

---

8.

#include <iostream>
using namespace std;

class MyIntStack {
	int* p;
	int size;
	int tos;
public:
	MyIntStack();
	MyIntStack(int size);
	MyIntStack(const MyIntStack& s);
	~MyIntStack();
	bool push(int n);
	bool pop(int& n);
	
};

MyIntStack::MyIntStack() {
	tos = -1;
	size = 1;
	p = new int[size];
}

MyIntStack::MyIntStack(int size) {
	this->size = size;
	tos = -1;
	p = new int[size];
}

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

MyIntStack::MyIntStack(const MyIntStack& s) {
	tos = s.tos;
	size = s.size;
	p = new int[size];
	for (int i = 0; i < size; i++) {
		p[i] = s.p[i];
	}
}

bool MyIntStack::push(int n) {
	if (tos == size - 1) 
		return false;
	else {
		p[++tos] = n;
		return true;
	}
}

bool MyIntStack::pop(int& n) {
	if (tos == -1) 
		return false;
	else {
		n = p[tos--];
		return true;
	}
}
 
int main() {
	MyIntStack a(10);
	a.push(10);
	a.push(20);
	MyIntStack b = a;
	b.push(30);

	int n;
	a.pop(n);
	cout << "스택 a에서 팝한 값 " << n << endl;
	b.pop(n);
	cout << "스택 b에서 팝한 값 " << n << endl;
}

---

9 return *this;

#include <iostream>
using namespace std;

class Accumulator {
	int value;
public:
	Accumulator(int value) { this->value = value; }
	Accumulator& add(int n);
	int get() { return value; }
};

Accumulator& Accumulator::add(int n) {
	value += n;
	return *this;
}

int main() {
	Accumulator acc(10);
	acc.add(5).add(6).add(7); // acc의 value 멤버가 28이 된다.
	cout << acc.get() << endl; // 28 출력
}

---

10. 

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

class Buffer {
	string text;
public:
	Buffer(string text) { this->text = text; }
	void add(string next) { text += next; }
	void print() { cout << text << endl; }
};

Buffer& append(Buffer &buf, string text) {
	buf.add(text);
	return buf;
}

int main() {
	Buffer buf("Hello");
	Buffer& temp = append(buf, "Guys");
	temp.print();
	buf.print();

}