[어서와 C++는 처음이지!] CH6 Exercise

1

• 벡터 크기 설정

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

int main() {
	int n;
	cout << "정수의 개수: ";
	cin >> n;

	vector<int> v(n);
	for (auto& e : v) {
		cout << "정수를 입력하시오: ";
		cin >> e;
	}

	int max = v[0];
	int min = v[0];
	for (auto& e : v) {
		if (e > max)
			max = e;
		if (e < min)
			min = e;
	}
	cout << "최대값: " << max << endl;
	cout << "최소값: " << min << endl;

	return 0;
}

 

2

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

int main() {
	int n;
	cout << "문자열의 개수: ";
	cin >> n;

	vector<string> v(n);  // 벡터 크기 지정
	for (auto& e : v) {
		cout << "문자열을 입력하시오: ";
		cin >> e;
	}

	for (auto& e : v) {
		cout << e << endl;
	}

	return 0;
}

 

3

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

class Rect {
public:
	int w, h;

	Rect() {
		w = 0;
		h = 0;
	}

	Rect(int _w, int _h) {
		w = _w;
		h = _h;
	}

	int area() {
		return w * h;
	}

	void print() {
		cout << "(" << w << ", " << h << ")" << endl;
	}
};

int main() {
	int n;
	cout << "사각형의 개수: ";
	cin >> n;

	vector<Rect> myRect(n);

	for (auto& e : myRect) {
		cout << "사각형의 폭: ";
		cin >> e.w;
		cout << "사각형의 높이: ";
		cin >> e.h;
	}

	for (auto& e : myRect) {
		if (e.area() > 100)
			e.print();
	}

	return 0;
}

 

4

/* 객체 배열 이용하기 */
#include <iostream>
#include <string>
using namespace std;

class SMS {
public:
	string sender;
	string receiver;
	string text;

	SMS() {
		sender = "0";
		receiver = "0";
		text = "0";
	}

	SMS(string s, string r, string t) {
		sender = s;
		receiver = r;
		text = t;
	}

	void print() {
		cout << "발신자: " << sender << " ";
		cout << "수신자: " << receiver << " ";
		cout << "내용: " << text << endl;
	}
};

int main() {
	SMS mySMS[2];
	mySMS[0] = { "010-1234-5678", "010-1208-3719", "C++ 공부는 잘 돼가나요?" };
	mySMS[1] = { "010-1223-1423", "010-1928-1283", "네 5장까지는 문제 없네요." };

	for (auto& e : mySMS)
		e.print();

	return 0;
}

 

/* 벡터 이용하기 */
#include <iostream>
#include <string>
#include <vector>
using namespace std;

class SMS {
public:
	string sender;
	string receiver;
	string text;

	SMS() {
		sender = "0";
		receiver = "0";
		text = "0";
	}

	SMS(string s, string r, string t) {
		sender = s;
		receiver = r;
		text = t;
	}

	void print() {
		cout << "발신자: " << sender << " ";
		cout << "수신자: " << receiver << " ";
		cout << "내용: " << text << endl;
	}
};

int main() {
	vector<SMS> mySMS(2);
	mySMS[0] = { "010-1234-5678", "010-1208-3719", "C++ 공부는 잘 돼가나요?" };
	mySMS[1] = { "010-1223-1423", "010-1928-1283", "네 5장까지는 문제 없네요." };

	for (auto& e : mySMS) {
		e.print();
	}

	return 0;
}

 

5: 정렬 알고리즘

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

class Student {
public:
	string name;
	double marks;

	Student() {
		name = "0";
		marks = 0;
	}

	Student(string n, double m) {
		name = n;
		marks = m;
	}

	// get_marks()
	double get_marks() {
		return marks;
	}

	void print() {
		cout << "이름 : " << name << endl;
		cout << "학점 : " << marks << endl;
	}
};

// compare
bool compare(Student& a, Student& b) {
	return a.marks > b.marks;
}

int main() {
	vector<Student> myStudent(3);

	for (auto& e : myStudent) {
		cout << "이름 : ";
		cin >> e.name;
		cout << "학점 : ";
		cin >> e.marks;
	}

	// 정렬 알고리즘
	sort(myStudent.begin(), myStudent.end(), compare);

	for (auto& e : myStudent) {
		e.print();
	}

	return 0;
}

 

6

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

class Contact {
public:
	string name;
	string tel;
};

int main() {
	vector<Contact> myContact(3);

	for (auto& e : myContact) {
		cout << "이름을 입력하시오: ";
		cin >> e.name;
		cout << "전화번호를 입력하시오: ";
		cin >> e.tel;
	}

	string input;
	cout << "탐색하고 싶은 이름을 입력하시오: ";
	cin >> input;
	for (auto& e : myContact) {
		if (input == e.name)
			cout << "전화번호: " << e.tel << endl;
	}

	return 0;
}