[C++] 명품 C++ 프로그래밍 6장

실습문제

1번

#include <iostream>
using namespace std;

int add(int *a, int size, int *b = NULL) {
	int sum = 0;
	for (int i = 0; i < size; i++) {
		sum += a[i];
	}
	if (b != NULL) {
		for (int i = 0; i < size; i++) {
			sum += b[i];
		}
	}
	return sum;
}

int main() {
	int a[] = { 1,2,3,4,5 };
	int b[] = { 6,7,8,9,10 };
	int c = add(a, 5);
	int d = add(a, 5, b);
	cout << c << endl;
	cout << d << endl;
}

1번

 

2번

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

class Person {
	int id;
	double weight;
	string name;
public:
	Person(int id = 1, string name = "Grace", double weight = 20.5) {
		this->id = id;
		this->name = name;
		this->weight = weight;
	}
	void show() { cout << id << ' ' << weight << ' ' << name << endl; }
};

int main() {
	Person grace, ashley(2, "Ashley"), helen(3, "Helen", 32.5);
	grace.show();
	ashley.show();
	helen.show();
}

2번

 

3번

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

int big(int a, int b, int c = 100) {
	return (a > b ? a : b) < c ? (a > b ? a : b) : c;
}

int main() {
	int x = big(3, 5);
	int y = big(300, 60);
	int z = big(30, 60, 50);
	cout << x << ' ' << y << ' ' << z << endl;
	return 0;
}

3번

 

4번

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

class MyVector {
	int* mem;
	int size;
public:
	MyVector(int n, int val);
	~MyVector() { delete[] mem; }
	void show();
};
MyVector::MyVector(int n = 100, int val = 0) {
	mem = new int[n];
	size = n;
	for (int i = 0; i < size; i++) mem[i] = val;
}
void MyVector::show() {
	for (int i = 0; i < size; i++) {
		cout << mem[i] << ' ';
	}
	cout << endl;
}

int main() {
	MyVector one, two(50, 1);
	one.show();
	two.show();
}

4번

 

 

5번

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

class ArrayUtility {
public:
	static void intToDouble(int source[], double dest[], int size);
	static void doubleToInt(double source[], int dest[], int size);
};
void ArrayUtility::intToDouble(int source[], double dest[], int size) {
	for (int i = 0; i < size; i++) {
		dest[i] = (double)source[i];
	}
}
void ArrayUtility::doubleToInt(double source[], int dest[], int size) {
	for (int i = 0; i < size; i++) {
		dest[i] = (int)source[i];
	}
}

int main() {
	int x[] = { 1,2,3,4,5 };
	double y[5];
	double z[] = { 9.9, 8.8, 7.7, 6.6, 5.6 };

	ArrayUtility::intToDouble(x, y, 5);
	for (int i = 0; i < 5; i++)cout << y[i] << ' ';
	cout << endl;

	ArrayUtility::doubleToInt(z, x, 5);
	for (int i = 0; i < 5; i++)cout << x[i] << ' ';
	cout << endl;
}

5번

 

6번

#include <iostream>
#include <string>

using namespace std;

class ArrayUtility2 {
public:
	static int* concat(int s1[], int s2[], int size);
	static int* remove(int s1[], int s2[], int size, int& retSize);
};
int* ArrayUtility2::concat(int s1[], int s2[], int size) {
	int* ret = new int[size];
	int ind = 0;
	cout << "합친 정수 배열을 출력한다." << endl;
	for (int i = 0; i < size / 2; i++) {
		ret[ind] = s1[i];
		cout << ret[ind] << ' ';
		ind++;
	}
	for (int i = 0; i < size / 2; i++) {
		ret[ind] = s2[i];
		cout << ret[ind] << ' ';
		ind++;
	}
	cout << endl;

	return ret;
}
int* ArrayUtility2::remove(int s1[], int s2[], int size, int& retSize) {
	int cnt = 0;
	int* tmp = new int[size];

	for (int i = 0; i < size; i++) {
		for (int j = 0; j < size; j++) {
			if (s1[i] == s2[j]) break;
			if (j == size-1) tmp[cnt++] = s1[i];
		}
	}
	if (cnt == 0) return NULL;

	retSize = cnt;
	cout << "배열 x[]에서 y[]를 뺀 결과를 출력한다. 개수는 " << retSize << endl;
	int* ret = new int[retSize];
	for (int i = 0; i < retSize; i++) {
		ret[i] = tmp[i];
		cout << ret[i] << ' ';
	}
	cout << endl;

	return ret;
}

int main() {
	int x[5], y[5], retSize;
	int* z, * w;

	cout << "정수를 5개 입력하라. 배열 x에 삽입한다>>";
	for (int i = 0; i < 5; i++) {
		cin >> x[i];
	}
	cout << "정수를 5개 입력하라. 배열 y에 삽입한다>>";
	for (int i = 0; i < 5; i++) {
		cin >> y[i];
	}
	z = ArrayUtility2::concat(x, y, 10);
	w = ArrayUtility2::remove(x, y, 5, retSize);
}

6번

 

7번

#include <iostream>
#include <ctime>
#include <cstdlib>

using namespace std;

class Random {
public:
	static void seed() { srand((unsigned)time(0)); }
	static int nextInt(int min = 0, int max = 32767);
	static char nextAlphabet();
	static double nextDouble();
};
int Random::nextInt(int min, int max) {
	return rand() % (max - min) + min;
}
char Random::nextAlphabet() {
	if (rand() % 2 == 0) return rand() % 26 + 'a';
	else return rand() % 26 + 'A';
}
double Random::nextDouble() {
	return (double)rand() / RAND_MAX;
}

int main() {
	cout << "1에서 100까지 랜덤한 정수 10개를 출력합니다" << endl;
	for (int i = 0; i < 10; i++) {
		cout << Random::nextInt(1, 100) << ' ';
	}
	cout << endl;

	cout << "알파벳을 랜덤하게 10개 출력합니다" << endl;
	for (int i = 0; i < 10; i++) {
		cout << Random::nextAlphabet() << ' ';
	}
	cout << endl;

	cout << "랜덤한 실수 10개를 출력합니다" << endl;
	for (int i = 0; i < 10; i++) {
		cout << Random::nextDouble() << ' ';
	}
	cout << endl;
}

7번

 

8번

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


class Trace{
public:
    static int idx;
    static string t[100][2];
    static void put(string a, string b);
    static void print(string word="");
};
string Trace::t[100][2] = {""};
int Trace::idx = 0;
void Trace::put(string a, string b){
    t[idx][0] = a;
    t[idx][1] = b;
    idx++;
}
void Trace::print(string word){
    if(word == ""){
        cout << "----- 모든 Trace 정보를 출력합니다. -----" << endl;
        for(int i  = 0; i < idx; i++){
            cout << t[i][0] << " : " << t[i][1] << endl;
        }
    }
    else{
        cout << "----- "<< word << "태그의 Trace 정보를 출력합니다. -----" << endl;
        for(int i = 0; i < idx; i++){
            if(t[i][0].compare(word) == 0){
                cout << t[i][0] << ":" << t[i][1] << endl;
            }
        }
    }
}


void f(){
    int a, b, c;
    cout << "두 개의 정수를 입력하세요 >>";
    cin >> a >> b;
    Trace::put("f()", "정수를 입력 받았음");
    c = a + b;
    Trace::put("f()", "합 계산");
    cout << "합은" << c << endl;
}

int main(){
    Trace::put("main()", "프로그램 시작합니다.");
    f();
    Trace::put("main()", "종료");
    Trace::print("f()");
    Trace::print();
}

8번

 

9번

#include <iostream>
using namespace std;

class Board{
public:
    static string *boards;
    static int idx;
    static void add(string word);
    static void print();
};
string* Board::boards = new string[100];
int Board::idx = 0;
void Board::add(string word){
    boards[idx] = word;
    idx ++;
}
void Board::print(){
    cout << "********** 게시판입니다. **********";
    cout << endl;
    for(int i = 0; i < idx; i++){
        cout << i << ": " << boards[i] << endl;
    }
}

int main() {
	Board::add("중간고사는 감독 없는 자율 시험입니다.");
	Board::add("코딩 라운지 많이 이용해 주세요.");
	Board::print();
	Board::add("진소린 학생이 경진대회 입상하였습니다. 축하해주세요");
	Board::print();
}

9번