~cpp 
// Data.h

#ifndef _DATA_H_
#define _DATA_H_

class Data{
private:
	char name[20]; 
    int number;
    int kor;
    int eng; 
    int math;
    int total;
    double ave;
    char grade[2];
public:
	Data();
	Data(char na[], int nu, int k, int e, int m);
	int showNumber(int select);
	char * showName();
	int showNum();
	int showTotal();
	double showAve();
};

#endif

~cpp 
//Judgement.h

#ifndef _JUDGEMENT_H_
#define _JUDGEMENT_H_

#include "Data.h"
#include "Order.h"

class Judgement{
private:
	int tempData;
	int tempNumber;
	int stData[20];
	int arrayNumber[20];
public:
	Judgement();
	void sort(bool IsItSort , int select , Data d[]);
	void outputAll(bool IsItAll, Data d[]);
	void outputPart(bool IsItPart, Data d[] , int select);
};


#endif

~cpp 
//Order.h

#ifndef _ORDER_H_
#define _ORDER_H_

class Order{
private:
	int mainmenu;
	int submenu;
public:
	Order();
	void menu();
	bool IsItAll();
	bool IsItSort();
	int subNumber();
};

#endif

~cpp 
// Data.cpp
#include <iostream>
using namespace std;
#include "Data.h"

Data::Data()
{
}

Data::Data(char na[], int nu, int k, int e , int m)
{
	strcpy(name, na);
    number = nu; 
    kor = k; 
    eng = e;
    math = m;
    total = k + e + m;
    ave = (double)total/3;
	for (int i = 0 ; i <= 19 ; i++ ) 
	{ 
		if ( ave >= 95 && ave <=100) 
			strcpy(grade,"a+"); 
		else if ( ave >= 90 && ave < 95) 
			strcpy(grade,"a"); 
		else if ( ave >= 85 && ave < 90) 
			strcpy(grade,"b+"); 
		else if ( ave >= 80 && ave < 85) 
			strcpy(grade,"b"); 
		else if ( ave >= 75 && ave < 80) 
			strcpy(grade,"c+"); 
		else if ( ave >= 70 && ave < 75) 
			strcpy(grade,"c"); 
		else if ( ave >= 65 && ave < 70) 
			strcpy(grade,"d+"); 
		else if ( ave >= 60 && ave < 65) 
			strcpy(grade,"d"); 
		else if ( ave <= 59) 
			strcpy(grade,"f");
	}
}

int Data::showNumber(int select)
{
	if (select == 1 )
		return kor;
	else if (select == 2 )
		return eng;
	else if (select == 3 )
		return math;
	else
		return 0;
}

char * Data::showName()
{
	return name;
}

int Data::showNum()
{
	return number;
}

int Data::showTotal()
{
	return total;
}

double Data::showAve()
{
	return ave;
}

~cpp 
//Judgement.cpp
#include <iostream>
using namespace std;
#include "Judgement.h"
#include "Data.h"
#include "Order.h"

Judgement::Judgement()
{
	for (int i = 0 ; i <= 19 ; i++)
		arrayNumber[i] = i;
}

void Judgement::sort(bool IsItSort , int select , Data d[])		// 소트 부분
{
	if (IsItSort)
	{
		if ( select == 0 )
			for (int k = 0 ; k <= 19 ; k++)		//
				stData[k] = d[k].showTotal();	//
		else						// 알맞는 데이터 값 카피
			for (int k = 0 ; k <= 19 ; k++)		//
				stData[k] = d[k].showNumber(select);	//

		for (int i = 0 ; i <= 19 ; i++)	{ 
			for (int j = i+1 ; j <= 19 ; j++) { 
				if ( stData[i] < stData[j] ) { 
					tempData = stData[i];
					tempNumber = arrayNumber[i];

					stData[i] = stData[j];
					arrayNumber[i] = arrayNumber[j];

					stData[j] = tempData; 
					arrayNumber[j] = tempNumber;
		} } }						// 소트
	}
}

void Judgement::outputAll(bool IsItAll, Data d[])
{
	if (IsItAll)
	{
		cout << "이름\t번호\t\t국어\t영어\t수학\t총점\t평균" << endl; 
		for (int i = 0 ; i <= 19 ; i++){
			cout << d[arrayNumber[i]].showName()
				 << "\t" << d[arrayNumber[i]].showNum() 
				 << "\t" << d[arrayNumber[i]].showNumber(1)
				 << "\t" << d[arrayNumber[i]].showNumber(2)
				 << "\t" << d[arrayNumber[i]].showNumber(3)
				 << "\t" << d[arrayNumber[i]].showTotal()
				 << "\t" << d[arrayNumber[i]].showAve()
				 << endl;
		}
		cin.get();
		cin.get();
	}
}

void Judgement::outputPart(bool IsItPart, Data d[] , int select)
{
	if (IsItPart)
	{
		cout << "이름\t번호\t";
		if ( select == 1 )
			cout << "\t국어" << endl;
		else if ( select == 2 )
			cout << "\t영어" << endl;
		else if ( select == 3 )
			cout << "\t수학" << endl; 
		for (int i = 0 ; i <= 19 ; i++){
			cout << d[arrayNumber[i]].showName()
				 << "\t" << d[arrayNumber[i]].showNum() 
				 << "\t" << d[arrayNumber[i]].showNumber(select)
				 << endl;
		}
		cin.get();
		cin.get();
	}
}

~cpp 
//Order.cpp
#include <iostream>
using namespace std;
#include "Order.h"

Order::Order()
{
	submenu = 0;
}

bool Order::IsItAll()
{
	if (mainmenu == 3 || mainmenu == 4)
		return true;
	else
		return false;

}

bool Order::IsItSort()
{
	if (mainmenu == 2 || mainmenu == 4)
		return true;
	else
		return false;
}

void Order::menu()
{
	system("cls");
	cout << "\t◆ 메뉴 ◆" << endl  
		<< "1) 과목별 입력 결과 리스트 " << endl 
		<< "2) 과목별 성적순 리스트 " << endl 
		<< "3) 학생 전과목 입력 결과 리스트 " << endl 
		<< "4) 학생 전과목 성적순 리스트 " << endl 
		<< "5) 종료 " << endl << endl 
		<< "메뉴를 선택하세요 -> ";
	cin >> mainmenu;
	if (mainmenu == 5)
		exit(1);
	if (mainmenu == 1 || mainmenu == 2)
	{
		system("cls");
		cout << "\t◇과목 선택 메뉴◇" << endl 
			<< "1) 국어" << endl 
			<< "2) 영어" << endl 
			<< "3) 수학" << endl 
			<< "과목을 선택하세요 -> ";
		cin >> submenu;
	}

}

int Order::subNumber()
{
	return submenu;
}

~cpp 
#include <iostream>
using namespace std;

#include "Data.h"
#include "Judgement.h"
#include "Order.h"

Data data[] = { 
		Data( "고재선" ,20025301, 85, 90, 80 ), 
		Data( "권현진" ,20025302, 80, 88, 85 ),  
		Data( "김동욱" ,20025303, 88, 93, 75 ), 
		Data( "김무영" ,20025309, 75, 85, 70 ), 
		Data( "김민재" ,20025307, 73, 83, 77 ), 
		Data( "김성원" ,20025304, 95, 88, 80 ), 
		Data( "김영준" ,20025308, 95, 88, 80 ), 
		Data( "김윤섭" ,20025305, 94, 70, 65 ), 
		Data( "김철호" ,20025306, 80, 75, 88 ), 
		Data( "김태완" ,20025310, 65, 73, 94 ), 
		Data( "김태완" ,20025313, 77, 78, 99 ), 
		Data( "김희균" ,20025312, 80, 77, 85 ), 
		Data( "류재현" ,20025311, 95, 80, 95 ), 
		Data( "문구봉" ,20025315, 78, 90, 75 ), 
		Data( "박대원" ,20025314, 90, 95, 65 ), 
		Data( "박세연" ,20025316, 88, 88, 80 ), 
		Data( "박준성" ,20025317, 83, 76, 75 ), 
		Data( "서수원" ,20025318, 75, 68, 70 ), 
		Data( "양민우" ,20025319, 65, 70, 80 ), 
		Data( "양정은" ,20025320, 88, 85, 90 )
};

int main()
{
	while (1)
	{
		Judgement judgement;
		Order order;
		order.menu();
		judgement.sort(order.IsItSort(), order.subNumber(), data);
		judgement.outputAll(order.IsItAll(), data);
		judgement.outputPart(!(order.IsItAll()), data, order.subNumber());
	}
	return 0;
}