1. 부서 번호가 10번인 부서의 사람 중 사원번호, 이름, 급여를 출력해라.
select empno, ename, sal
from emp
where deptno=10;

2. 사원번호가 7369인 사람 중 이름, 입사일, 부서번호를 출력해라.
select ename, hiredate, deptno
from emp
where empno=7369;

3. 이름이 ALLEN인 사람의 모든 정보를 출력하여라.
select *
from emp
where ename='ALLEN';

4. 입사일이 87/04/19인 사원의 이름, 부서번호, 급여를 출력해라.
select ename, deptno, sal
from emp
where hiredate='87/04/19';

5. 직업이 MANAGER가 아닌 사람의 모든 정보를 출력해라.
select *
from emp
where  job!='MANAGER';

6. 입사일이 81/04/02 이후에 입사한 사원의 정보를 출력해라.
select *
from emp
where hiredate>'81/04/02';

7. 급여가 800이상인 사람의 이름, 급여, 부서번호를 출력해라.
select empno, sal, deptno
from emp
where sal>=800;

8. 부서번호가 20번 이상인 사원의 모든 정보를 출력해라.
select *
from emp
where deptno>=20;

9. 입사일이 81/12/09보다 먼저 입사한 사람들의 모든 정보를 출력해라.
select *
from emp
where hiredate<'81/12/09';

10. 사원번호가 7698보다 작거나 같은 사람들의 입사번호와 이름을 출력해라.
select empno, ename
from emp
where empno<=7698;

11. 입사일이 81/04/02보다 늦고 82/12/09보다 빠른 사원의 이름, 급여, 부서번호를 출력해라.
select ename, sal, deptno
from emp
where hiredate between '81/04/20' and '82/12/09';

12. 급여가 1600보다 크고 3000보다 작은 사람의 이름, 직업, 급여를 출력해라.
select ename, job, sal
from emp
where sal>1600 and sal<3000;

13. 사원번호가 7654와 7782사이 이외의 사원의 모든 정보를 출력해라.
select *
from emp
where empno not between 7654 and 7782;

14. 입사일이 81년 이외에 입사한 사원의 모든 정보를 출력해라.
select *
from emp
where hiredate not between '81/1/1' and '81/12/31';

15. 직업이 MANAGER와 SALESMAN인 사원의 모든 정보를 출력해라.
select ename, empno
from emp
where job in('MANAGER', 'SALESMAN');

16. 부서번호가 20, 30번을 제외한 모든 사원의 이름, 사원번호를 출력해라.
select ename, empno
from emp
where deptno not in(20, 30);

17. 이름이 S로 시작하는 사원의 사원번호, 이름, 입사일, 부서번호를 출력해라.
select empno, ename, hiredate, deptno
from emp
where ename like 'S%';

18. 입사일이 81년도인 사원의 모든 정보를 출력해라.
select *
from emp
where hiredate between '81/1/1' and '81/12/31';

19. 이름 중 S자가 들어가 있는 사람만 모든 정보를 출력해라.
select *
from emp
where ename like '%S%';

20. 이름이 S자로 시작하고 마지막 글자가 T인 사람의 모든 정보를 출력해라.(이때, 이름의 전체 글자수는 5자리이다.)
select *
from emp
where ename like 'S___T';

21. 첫 번째 문자는 관계없고 두 번째 문자가 A인 사원의 모든 정보를 출력해라.
select *
from emp
where ename like '_A%';

22. 커미션이 NULL인 사람의 정보를 출력해라.
select *
from emp
where comm is null;

23. 부서가 30번 부서이고 급여가 500이상인 사람의 이름, 부서, 급여를 출력하라.
select ename, deptno, sal
from emp
where deptno=30 and sal>=500;

24. 이름의 첫 글자가 K로 시작하거나 부서번호가 30인 사람의 사원번호, 이름, 부서번호를 출력하라.
select empno, ename, deptno
from emp
where ename like 'K%' and deptno=30;

25. 급여가 1500이상이고 부서번호가 30번인 사원중 직업이 MANAGER인 사원의 모든 정보를 출력하여라.
select *
from emp
where sal>=1500 and deptno=30 and job='MANAGER';

* 비교연산자
a=b : a는 b와 같다.
a<>b : a와 b는 같지 않다.
a>b : a는 b보다 크다(초과)
a>=b : a는 b보다 크거나 같다(이상)
a<b : a는 b보다 작다(미만)
a<=b : a는 b보다 작거나 같다(이하)

- 예제
1. 급여가 1500이상 2850이하 사원출력
select ename, sal
from emp
where sal>=1500 and sal<=2850
order by sal asc;
혹은
select ename, sal
from emp
where sal between 1500 and 2850
order by sal asc;

*논리연산자
or, and, not

*in(값, 값, ...)
not in(값, 값, ...)

예제
1. 사원명, 부서번호조회 부서번호가 10 또는 20 조회
 select ename, deptno
 from emp
 where deptno=10 or deptno=20 -> 같은 의미로  where deptno in(10, 20)
                                             -> 부정의의미 where deptno not in(10, 20)
 order by deptno asc;

2. 10과 30사이
select ename,deptno
from emp
where deptno not between 10 and 20
order by deptno asc;

*연결연산자 : ||
*함수명(~, ~, ~) parameter, argument, 인수, 인자

concat(표현식, 표현식) 인수가 2개밖에 들어갈수 있다.
현재날짜와 시간조회

*2009/06/22 09:41:30 이런형태로 출력하려면...
to_char(날짜, '날짜시간Format') 중요함...
to_char(sysdate, 'yyyy/mm/dd hh:mi:ss')

select sysdate, to_char(sysdate, 'bc yyyy/mon/dd day hh24:mi:ss am')
from dual;

* alter session set nls_date_format='날짜시간format'

*조건
select ~
from 테이블명
[where 조건]
[order by 정렬기준 정렬방법];

- 데이터타입 : 문자. 날짜 '~'

예제
- allen의 사원번호, 급여, 입사일조회
select empno, sal, hiredate
from emp
where ename='ALLEN';

*소문자를 대문자로 변환하는 함수
upper(~)

예제
select empno, sal, hiredate
from emp
where ename=upper('allen');

*lower(~)
대문자를 소문자로 출력시키는 함수

*앞글자만 대문자로...
initcap(~)

select empno, sal, lower(ename), initcap(ename), hiredate
from emp
where ename=upper('allen');

81/09/28에 입사한 사원명, 입사일, 급여, 커미션 조회
select ename, hiredate, sal, comm
from emp
where hiredate='81/09/28';

- 예제
1. xx번 부서는 ~~~ =>  출력 concat함수 + ~ 사용
select concat(deptno, concat('번 부서 : ', dname))
from dept;
OR
select deptno||concat('번 부서 : ', dname)
from dept;

2. 커미션이 확정된 사원의 사원번호, 사원명, 급여, 커미션 조회
select empno, ename, sal, comm
from emp
where comm is not null;

3. 2번 결과내 급여가 1500이상인 사원번호, 사원명, 급여, 커미션 조회
select empno, ename, sal, comm
from emp
where comm is not null and sal>=1500;

4. 3번의 결과를 급여 오름차순 조회
select empno, ename, sal, comm
from emp
where comm is not null and sal>=1500;
order by sal asc;

5. 10번 또는 20번 부서에 근무하는 사원들의
부서번호, 사원명, 급여, 커미션, bonus를 bonus 오름차순, 동일보너스 내 사원명 오름차순
bonus=기본커미션+300 커미션이 null이면 50을 기본 커미션으로 한다.
select deptno, ename, sal, nvl(comm, 50), nvl(comm, 50)+300 as bonus
from emp
where deptno in(10, 20)
order by bonus asc, ename asc;

* select 문법
select {* | 컬럼명}
from table명
order by 정렬기준 정렬방법, [정렬기준 정렬방법];

* 특정컬럼조회
- dept(부서테이블)
DEPTNO : 부서번호 (기본키 = primary key)
DNAME : 부서명
LOC : 지역

- emp(사원)
EMPNO : 사원번호 (기본키 = primary key)
ENAME : 사원명
JOB : 업무
MGR : 상사
HIREDATE: 입사일
SAL : 급여
COMM : 커미션
DEPTNO : 부서번호 (외래키 = foreign key)

- salgrade(급여등급)
GRADE : 호봉
LOSAL : 최저임금
HISAL : 최고임금

- 예제
1. dept 테이블에서 부서번호와 부서명 조회
select deptno, dname
from dept;

2. 사원테이블에서 사원번호, 사원명, 업무, 업무입사일 조회
select empno, ename, job, hiredate
from emp;

3. 사원테이블에서 사원번호, 사원명, 급여, 커미션, 부서번호 조회
select empno, ename, sal, comm, deptno
from emp;

* 정렬
오름차순(asc) : 숫자 작음 -> 큼 , 문자 a->z A->Z ㄱ->ㅎ날짜 예전->최근
내림차순(desc) : 숫자 큼 -> 작음, 문자 z->a Z->A ㅎ->ㄱ 날짜 최근->예전

*distinct : 중복되는 컬럼을 한번씩만 보여줌

- 예제
1. 부서테이블에서 부서명 내림차순 조회
select distinct *
from dept
order by dname desc;

2. 동일부서내 급여를 많이 받는 사원부터 조회
select *
from emp
order by sal desc;

3. 동일부서내에 급여를 많이 받는 사원부터 출력하되 급여가 동일하다면 이름 오름차순
select *
from emp
order by sal desc, ename asc;

* 별칭
- 칼럼명 [as] 칼럼alias
- 칼럼명 "칼럼alias" : "~~"에는 소문자, 대소문자, 공백, 한글

* null의 의미
0(zero)도 아니고, 빈공간도 아니다. 
미확정(해당사항 없음), 알수 없는(unknown) 값을 의미한다.
어떤 값인지 알 수 없지만 어떤 값이 존재하고 있다.
? 혹은 ∞의 의미이므로 연산, 할당, 비교가 불가능하다.

*산술연산
+, -, *, /

* dual 테이블
산술연산이나 가상컬럼 등의 값을 한번만 출력하고 싶을 때 많이 사용하는 테이블

- 예제
오늘 날짜를 한번만 출력
select sysdate
from dual;

/* v1.0 성적표

학생이 몇명인지 물어본다.

국어,영어,수학 점수 입력한다.

평균 계산해서 입출력한다.

#include <iostream.h>

class Student

{

private:

             int *kor;

             int *eng;

             int *math;

             int *ave;

public:

             void stu_input(int num)     //학생 성적 입력

             {

                           kor=new int[num];

                           eng=new int[num];

                           math=new int[num];

                           for(int i=0;i<num;i++)

                           {

                                        cout<<i+1<<"번의 국어 점수를 입력하세요.";

                                        cin>>kor[i];

                                        cout<<i+1<<"번의 영어 점수를 입력하세요.";

                                        cin>>eng[i];

                                        cout<<i+1<<"번의 수학 점수를 입력하세요.";

                                        cin>>math[i];

                                        cout<<"-----------------------------\n";

                           }

             }

             void stu_ave(int num)       //학생 평균

             {

                           ave=new int[num];

                           for(int i=0;i<num;i++)

                           {

                                        ave[i]=(kor[i]+eng[i]+math[i])/3;

                                        cout<<i+1<<"번의 학생의 평균은 "<<ave[i]<<"점입니다.\n";

                                        cout<<"----------------------------------\n";

                           }

             }

};

void main()

{

             Student stu;

             int num;

             cout<<"학생이 몇명입니까?";

             cin>>num;

             stu.stu_input(num);

             stu.stu_ave(num);

}*/

/* 성적표 v1.5

추가사항

메뉴 : 1.성적추가 2.성적출력 3.종료

성적출력하면 반평균 추가한다.*/

/*

#include <iostream.h>

class Student

{

private:

             int *kor;

             int *eng;

             int *math;

             int *student_ave;

             int class_ave;

public:

             void stu_input(int num)     //학생 성적 입력

             {

                           kor=new int[num];

                           eng=new int[num];

                           math=new int[num];

                           for(int i=0;i<num;i++)

                           {

                                        cout<<i+1<<"번의 국어 점수를 입력하세요.";

                                        cin>>kor[i];

                                        cout<<i+1<<"번의 영어 점수를 입력하세요.";

                                        cin>>eng[i];

                                        cout<<i+1<<"번의 수학 점수를 입력하세요.";

                                        cin>>math[i];

                                        cout<<"-----------------------------\n";

                           }

             }

             void stu_output(int num)   //학생 개인 성적과 평균 출력

             {

                           student_ave=new int[num];

                           for(int i=0;i<num;i++)

                           {

                                        student_ave[i]=(kor[i]+eng[i]+math[i])/3;

                                        cout<<i+1<<"번 학생\n";

                                        cout<<"국어 영어 수학 평균\n";

                                        cout<<" "<<kor[i]<<"   "<<eng[i]<<"   "<<math[i]<<"   "<<student_ave[i]<<endl;

                                        cout<<"----------------------------------\n";

                           }

             }

             void Class_ave(int num)   //반 평균 출력

             {

                           class_ave=0;

                           for(int i=0;i<num;i++)

                           {

                                        class_ave+=student_ave[i];

                           }

                           class_ave=class_ave/num;

                           cout<<"반평균은 "<<class_ave<<"점입니다.\n";

                           cout<<"종료합니다.\n";

             }

};

void main()

{

             Student stu;

             int num=0;

             int menu;

             for(;;)

             {

                           cout<<"메뉴를 선택하세요.\n";

                           cout<<"1.성적 입력 2. 성적출력 3.종료 \n";

                           cin>>menu;

                           if(menu==1)

                           {

                                        cout<<"학생이 몇명입니까?";

                                        cin>>num;

                                        stu.stu_input(num);

                           }

                           else if(menu==2)

                           {

                                        if(num==0)

                                        {

                                                     cout<<"입력된 값이 없습니다.\n";

                                        }

                                        else

                                        {

                                                     stu.stu_output(num);

                                        }

                           }

                           else if(menu==3)

                           {

                                        if(num==0)

                                        {

                                                     cout<<"입력된 값이 없습니다.\n";

                                        }

                                        else

                                        {

                                                     stu.Class_ave(num);

                                        }

                                        break;

                           }

                           else

                           {

                                        cout<<"다시 입력하세요.\n";

                           }

             }

}*/

/*성적표 v2.0

메뉴추가 1.성적입력 2.성적출력 3.로드 4.저장 5.종료*/

//          파일의 저장과 로드

//          File *fopen(*filename,*mode);       파일을 연다.

//          mode에서 wt는 쓰기, rt는 읽기

//          fprintf 파일을 출력하는 함수

//          fclose 해체

#include <iostream.h>

#include <string.h>

class Student

{

private:

             int *kor;

             int *eng;

             int *math;

             int *student_ave;

             int class_ave;

public:

             void stu_input(int num)     //학생 성적 입력

             {

                           kor=new int[num];

                           eng=new int[num];

                           math=new int[num];

                           for(int i=0;i<num;i++)

                           {

                                        cout<<i+1<<"번의 국어 점수를 입력하세요.";

                                        cin>>kor[i];

                                        cout<<i+1<<"번의 영어 점수를 입력하세요.";

                                        cin>>eng[i];

                                        cout<<i+1<<"번의 수학 점수를 입력하세요.";

                                        cin>>math[i];

                                        cout<<"-----------------------------\n";

                           }

             }

             void stu_output(int num)   //학생 개인 성적과 평균 출력

             {

                           student_ave=new int[num];

                           for(int i=0;i<num;i++)

                           {

                                        student_ave[i]=(kor[i]+eng[i]+math[i])/3;

                                        cout<<i+1<<"번 학생\n";

                                        cout<<"국어 영어 수학 평균\n";

                                        cout<<" "<<kor[i]<<"   "<<eng[i]<<"   "<<math[i]<<"   "<<student_ave[i]<<endl;

                                        cout<<"----------------------------------\n";

                           }

             }

             void stu_load()

             {

                           FILE *f=fopen("text.txt","rt");

                           fgets(,f);

                           fclose(f);

             }

             void stu_save()

             {

                           FILE *f=fopen("text.txt","wt");

                           fputs(,f);

                           fclose(f);

             }

             void Class_ave(int num)   //반 평균 출력

             {

                           class_ave=0;

                           for(int i=0;i<num;i++)

                           {

                                        class_ave+=student_ave[i];

                           }

                           class_ave=class_ave/num;

                           cout<<"반평균은 "<<class_ave<<"점입니다.\n";

                           cout<<"종료합니다.\n";

             }

};

void main()

{

             Student stu;

             int num=0;

             int menu;

             for(;;)

             {

                           cout<<"메뉴를 선택하세요.\n";

                           cout<<"1.성적 입력 2. 성적출력 3.로드 4.저장 5.종료\n";

                           cin>>menu;

                           if(menu==1)         //성적입력

                           {

                                        cout<<"학생이 몇명입니까?";

                                        cin>>num;

                                        stu.stu_input(num);

                           }

                           else if(menu==2) //성적출력

                           {

                                        if(num==0)

                                        {

                                                     cout<<"입력된 값이 없습니다.\n";

                                        }

                                        else

                                        {

                                                     stu.stu_output(num);

                                        }

                           }

                           else if(menu==3) //로드

                           {

                                        if(num==0)

                                        {

                                                     cout<<"입력된 값이 없습니다.\n";

                                        }

                                        else

                                        {

                                                     stu.stu_load(num);

                                        }

                           }

                           else if(menu==4) //저장

                           {

                                        if(num==0)

                                        {

                                                     cout<<"입력된 값이 없습니다.\n";

                                        }

                                        else

                                        {

                                                     stu.stu_save(num);

                                        }

                           }

                           else if(menu==5) //종료

                           {

                                        if(num==0)

                                        {

                                                     cout<<"입력된 값이 없습니다.\n";

                                        }

                                        else

                                        {

                                                     stu.Class_ave(num);

                                        }

                                        break;

                           }

                           else       //잘못 입력했을때

                           {

                                        cout<<"다시 입력하세요.\n";

                           }

             }

}

ee.h

//class로 계산기를 만들기

#include <iostream.h>

class Cal

{

private:

             int add_sum;       //더하기

             int sub_sum;       //빼기

             int mul_sum;       //곱하기

             int divi_sum;        //나누기

             int result;                          //연산결과

public:

             void init()

             {

                           add_sum=0;

                           sub_sum=0;

                           mul_sum=0;

                           divi_sum=0;

             }

             void add(int a,int b)

             {

                           result=a+b;

                           cout<<a<<"+"<<b<<"="<<result<<endl;

                           add_sum++;

             }

             void sub(int a,int b)

             {

                           result=a-b;

                           cout<<a<<"-"<<b<<"="<<result<<endl;

                           sub_sum++;

             }

             void mul(int a,int b)

             {

                           result=a*b;

                           cout<<a<<"*"<<b<<"="<<result<<endl;

                           mul_sum++;

             }

             void divi(int a,int b)

             {

                           result=a/b;

                           cout<<a<<"/"<<b<<"="<<result<<endl;

                           divi_sum++;

             }

             void exit()

             {

                           cout<<"총 덧셈 연산은 "<<add_sum<<"번 했습니다.\n";

                           cout<<"총 뺄셈 연산은 "<<sub_sum<<"번 했습니다.\n";

                           cout<<"총 곱셈 연산은 "<<mul_sum<<"번 했습니다.\n";

                           cout<<"총 나눗셈 연산은 "<<divi_sum<<"번 했습니다.\n";

                           cout<<"종료합니다.\n";

             }

};

void main()

{

             int num1, num2;

             Cal cal;

             cal.init();

             for(;;)

             {

                           cout<<"어떤 연산을 할 것인지 선택하세요.\n";

                           cout<<"1:+, 2:-, 3:*, 4:/, 5:exit \n";

                           int cho;

                           cin>>cho;

                           if(cho==1)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.add(num1,num2);

                           }

                           else if(cho==2)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.sub(num1,num2);

                           }

                           else if(cho==3)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.mul(num1,num2);

                           }

                           else if(cho==4)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.divi(num1,num2);

                           }

                           else if(cho==5)

                           {

                                        cal.exit();

                                        break;

                           }

                           else

                           {

                                        cout<<"잘못입력하셨습니다.\n";

                           }

             }

}

//class로 계산기를 만들기

#include <iostream.h>

class Cal

{

private:

             int add_sum;       //더하기

             int sub_sum;       //빼기

             int mul_sum;       //곱하기

             int divi_sum;        //나누기

             int result;                          //연산결과

public:

             void init()

             {

                           add_sum=0;

                           sub_sum=0;

                           mul_sum=0;

                           divi_sum=0;

             }

             void add(int a,int b)

             {

                           result=a+b;

                           cout<<a<<"+"<<b<<"="<<result<<endl;

                           add_sum++;

             }

             void sub(int a,int b)

             {

                           result=a-b;

                           cout<<a<<"-"<<b<<"="<<result<<endl;

                           sub_sum++;

             }

             void mul(int a,int b)

             {

                           result=a*b;

                           cout<<a<<"*"<<b<<"="<<result<<endl;

                           mul_sum++;

             }

             void divi(int a,int b)

             {

                           result=a/b;

                           cout<<a<<"/"<<b<<"="<<result<<endl;

                           divi_sum++;

             }

             void exit()

             {

                           cout<<"총 덧셈 연산은 "<<add_sum<<"번 했습니다.\n";

                           cout<<"총 뺄셈 연산은 "<<sub_sum<<"번 했습니다.\n";

                           cout<<"총 곱셈 연산은 "<<mul_sum<<"번 했습니다.\n";

                           cout<<"총 나눗셈 연산은 "<<divi_sum<<"번 했습니다.\n";

                           cout<<"종료합니다.\n";

             }

};

void main()

{

             int num1, num2;

             Cal cal;

             cal.init();

             for(;;)

             {

                           cout<<"어떤 연산을 할 것인지 선택하세요.\n";

                           cout<<"1:+, 2:-, 3:*, 4:/, 5:exit \n";

                           int cho;

                           cin>>cho;

                           if(cho==1)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.add(num1,num2);

                           }

                           else if(cho==2)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.sub(num1,num2);

                           }

                           else if(cho==3)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.mul(num1,num2);

                           }

                           else if(cho==4)

                           {

                                        cout<<"두개의 숫자를 입력하세요.\n";

                                        cin>>num1>>num2;

                                        cal.divi(num1,num2);

                           }

                           else if(cho==5)

                           {

                                        cal.exit();

                                        break;

                           }

                           else

                           {

                                        cout<<"잘못입력하셨습니다.\n";

                           }

             }

}

*/

//생성자 소멸자

/*

#include <iostream.h>

class A

{

             int a;

public:

             A(int a)

             {

                           a=a;

                           cout<<"생성자 호출"<<a<<endl;

             }

             ~A()

             {

                           cout<<"소멸자 호출"<<a<<endl;

             }

};

void main()

{

             {

                           A a(1);

                           {

                                        A b(2);

                                        {

                                                     A c(3);

                                        }

                           }

             }

}

*/

/*

#include <iostream.h>

class Date

{

private:

             int year;

             int month;

             int day;

             int sum;

public:

             Date()

             {

             }

             int result(int year[2],int month[2],int day[2])

             {

                           year=year[1]-year[0];

                           month=month[1]-month[0];

                           day=day[1]-day[0];

                           sum=year*365+month*30+day;

                           return sum;

             }

};

void main()

{

             Date date;

             int year[2], month[2], day[2];

             cout<<"만난날을 몇년, 몇월, 몇일 순서대로 입력하세요.\n";

             cin>>year[0]>>month[0]>>day[0];

             cout<<"오늘 날짜를 입력하세요.\n";

             cin>>year[1]>>month[1]>>day[1];

             cout<<"총 만난날은 "<<date.result(int year[2],int month[2],int day[2])<<"일입니다.\n";

}

*/

/*

//ID와 비밀번호 클래스로, 동적할당

//사용자는

#include <iostream.h>

class user

{

private:

             char *ID;

             char *p;

public:

             void (char *c)

             {

                           int

             }

};

//몇명인지 물어본다.

void main()

{

             int num;

             cout<<"몇명을 입력합니까?";

             cin>>num;

             user *a=new int[num];

             for(int i=0;i<num;i++)

             {

                           cout<<"ID를 입력하세요.";

                           cin>>;

                           cout<<;

                           cin>>;

             }

             //동적할당으로 입력해서 클래스에서 동적할당

//입출력

}

*/

#include <iostream.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

class U

{

private:

             char *i;

             char *p;

             void input(char *ID,char *pass)

             {

                           int a=strlen(ID);

                           int b=strlen(pass);

                           i=new char[a+1];

                           p=new char[b+1];

                           strcpy(i,ID);

             }

             void output(char *ID,char *pass)

             {

             }

             ~U()

             {

                           delete[] i;

                           delete[] p;

             }

};

void main()

{

             int num;

             U *p=new U[num];

             char ID[128];

             char pass[128];

             for(int i=0;i<num;i++)

             {

                           cin>>ID;

                           cin>>pass;

                           p[i].input(ID,pass);

             }

             for(int j=0;j<num;j++)

             {

                           p[j].output(ID,pass);

             }

             delete[] p;

}

//문자열을 입력받아 문자를 거꾸로 바꿔서 출력하기.

/*

#include <iostream.h>

#include <stdio.h>

#include <string.h>

char* change(char *src)

{

             int len=strlen(src);

             char *Temp=new char[len+1];

             for(int i=0;i<len;i++)

             {

                           Temp[i]=src[len-1-i];

             }

             Temp[len]=NULL;

             return Temp;

}

void main()

{

             char ori[128];

             gets(ori);

             char *ch=change(ori);

             cout<<"원래 문자열 : "<<ori<<endl;

             cout<<"바뀐 문자열 : "<<ch<<endl;

             delete ch;

}

*/

//클래스

//구조체는 함수를 못담지만 클래스는 함수를 담을수 있다.

/*

#include <iostream.h>

class Man

{

public:

             char name[128];

             int age;

             int tall;

};

void main()

{

             Man *a;

             int num;

             cout<<"사람 수가 몇 명입니까?";

             cin>>num;

             a=new int[num];

             for(int i=0;i<num;i++)

             {

                           cout<<i+1<<"번째 사람의 이름을 입력하세요. ";

                           cin>>a.name;

                           cout<<"나이를 입력하세요. ";

                           cin>>a.age;

                           cout<<"키를 입력하세요. ";

                           cin>>a.tall;

             }

             for(int j=0;j<num;j++)

             {

                           cout<<"이름 : "<<a.name<<", 나이 : "<<a.age<<"살, 키 : "<<a.tall<<"cm\n";

             }

}

*/

#include <iostream.h>

class Man

{

private:

             char name[128];

             int tall;

             int age;

public:

             void Input()

             {

                           cout<<"이름 입력\n";

                           cin>>name;

                           cout<<"키 입력\n";

                           cin>>tall;

                           cout<<"나이 입력\n";

                           cin>>age;

             }

             void Output(char *s,int a,int b)

             {

                           cout<<s<<endl;

                           cout<<a<<endl;

                           cout<<b<<endl;

             }

};

void main()

{

             int num;

             cout<<"학생수 입력\n";

             Man a[num];

             for(int i=0;i<num;i++)

             {

                           a[i].Input();

             }

             for(int )

             a.Output("이름",180,19);

}

//숙제

/*

class student

{

private:

             //성적은 private

             int kor;

             int eng;

             void Input()

             {

             }

             void Output()//클래스 내에 해야됨.

             {

                           //번호순대로 총점과 평균을 출력한다.

};

void main

{

             //학생이 몇명?

             //동적할당한다.

             //번호별로 점수 입력

};

#include <iostream.h>

void main()

{

             int a,b;

             int sum;

             cout<<"숫자 2개를 입력하세요.\n";

             cin>>a>>b;

             if (a<b)

             {

                           for(sum=0,a+=1;a<b;a++)

                           {

                                        sum+=a;

                           }

             }

             else if (a>b)

             {

                           for(sum=0,b+=1;a>b;b++)

                           {

                                        sum+=b;

                           }

             }

             else

             {

                           sum=0;

             }

             cout<<"두 값 사이의 합은 "<<sum<<"입니다.\n";

}

*/

/*

#include <iostream.h>

void main()

{

             int num;

             cout<<"몇단을 출력할까요?\n";

             cin>>num;

             for(int i=1;i<=9;i++)

             {

                           cout<<num<<" * "<<i<<" = "<<num*i<<"\n";

             }

}

*/

//동적할당은 c++로

//int *p=(int *)malloc(4);

//int *p=new int;

//free(p);

//delete p;

//int *p=(int *)malloc(4*sizeof(int));

//int *p=new int[4];

#include <iostream.h>

void change(int *p,int num)

{

             num--;

             int *Temp=new int[num];

             for(int i=0;i<=num;i++)

             {

                           Temp[i]=p[num-i];

             }

             for(int j=0;j<=num;j++)

             {

                           p[j]=Temp[j];

             }

}

void main()

{

             cout<<"생성할 숫자의 갯수는?";

             int num;

             cin>>num;

             int *p=new int[num];

             for(int i=0;i<num;i++)

             {

                           p[i]=i+1;

             }           

             change(p,num);

             for(int j=0;j<num;j++)

             {

                           cout<<p[j]<<"\n";

             }

             delete p;

}

//숙제:3개의 반을 물어본다.

#include <stdio.h>

#include <stdlib.h>

#define Class 3

struct std

{

             int kor;

             int eng;

};

void input(std *s,int num[Class])

{

             int i,j;

             for(i=0;i<Class;i++)

             {

                           for(j=0;j<num[i];j++)

                           {

                                        printf("%d번의 학생의 국어점수를 입력하세요.",i+1);

                                        scanf("%d",&s[i].kor);

                                        printf("%d번의 학생의 영어점수를 입력하세요.",i+1);

                                        scanf("%d",&s[i].eng);

                                        printf("--------------------------------------\n");

                           }

             }

}

//%d반의 총 국어 평균, 영어 평균 제일 잘한반 %d반 출력하기

void output(std *s,int num[Class])

{

             int i;

             for(i=0;i<num;i++)

             {

                           printf("%d번 국어점수:%d점, 영어점수:%d점\n",i+1,s[i].kor,s[i].eng);

                           printf("-----------------------------------------\n");

             }

}

void main()

{           

             int num[Class];

             int i;

             std *s;  

             for(i=0;i<Class;i++)

             {

                           printf("%d반의 학생이 몇명입니까?",i+1);

                           scanf("%d",&num[Class]);

             }

             printf("--------------------\n");

             s=(std *)malloc(num[Class]*sizeof(std));

             input(s,num[Class]);

             output(s,num[Class]);

             free(s);

}

//          파일의 저장과 로드

//          File *fopen(*filename,*mode);       파일을 연다.

//          mode에서 wt는 쓰기, rt는 읽기

//          fprintf 파일을 출력하는 함수

//          fclose 해체

/*

#include <stdio.h>

void main()

{

//          int a=20;

             int b;

             FILE *f=fopen("test.txt","rt");

             fscanf(f,"%d",&b);

             printf("%d\n",b);

//          FILE *f=fopen("test.txt","wt");

//          fprintf(f,"%d",a);

             fclose(f);

}

*/

/*

#include <stdio.h>

#include <string.h>

void main()

{

             char sen1[128];

             char sen2[128];

             printf("문장을 입력하세요.\n");

             gets(sen1);

             FILE *f1=fopen("test.txt","wt");

             fputs(sen1,f1);

             fclose(f1);

             FILE *f2=fopen("test.txt","rt");

             printf("문장을 출력합니다.\n");

             fgets(sen2,sizeof(sen1),f2);

             puts(sen2);

             fclose(f2);

}

*/

//구구단

/*

#include <stdio.h>

void main()

{

             int i,j;

             FILE *f=fopen("99.txt","wt");

             for(i=2;i<=9;i++)

             {

                           for(j=1;j<=9;j++)

                           {

                                        printf("%d * %d = %d \n",i,j,i*j);

                           }

             }

             for(i=2;i<=9;i++)

             {

                           for(j=1;j<=9;j++)

                           {

                                        fprintf(f,"%d * %d = %d \n",i,j,i*j);

                           }

             }

             fclose(f);

}

*/

#include <stdio.h>

void main()

{

             int i,j,k;

             char a,b;

             k=i*j;

             FILE *f=fopen("99.txt","rt");

             for(i=2;i<=9;i++)

             {

                           for(j=1;j<=9;j++)

                           {

                                        fscanf(f,"%d %c %d %c %d",&i,&a,&j,&b,&k);

                                        printf("%d %c %d %c %d \n",i,a,j,b,k);

                           }

             }

             fclose(f);

}

#include <stdio.h>

struct A

{

             char name[128];

             int kor;

             int eng;

};

void main()

{

             int i;

             A P[5];

             for(i=0;i<5;i++)

             {

                           printf("%d번의 학생 이름을 입력하세요.",i+1);

                           scanf("%s",&P[i].name);

                           printf("국어 점수를 입력하세요.");

                           scanf("%d",&P[i].kor);

                           printf("영어 점수를 입력하세요.");

                           scanf("%d",&P[i].eng);

             }

             for(i=0;i<5;i++)

             {

                           printf("%s의 국어 점수 : %d, 영어 점수 : %d \n",P[i].name,P[i].kor,P[i].eng);

             }

}

#include <stdio.h>

#include <stdlib.h>

#include <time.h>

#include <string.h>

//동적할당

/*

void main()

{

             int num;

             int i;

             int *age;

             printf("가족의 수를 몇입니까?");

             scanf("%d",&num);

             age=(int *)malloc(num*sizeof(int));

             for(i=0;i<num;i++)

             {

                           printf("나이를 입력하세요.");

                           scanf("%d",&age[i]);

             }

             for(i=0;i<num;i++)

             {

                           printf("%d번째 식구의 나이는 %d살입니다.\n",i+1,age[i]);

             }

             free(age);

}*/

/*

#define cn 2

void main()

{

             int *Class[cn];

             int num[cn]; //학생수

             int i,j;

             for(i=0;i<cn;i++)

             {

                           printf("%d반의 학생의 수 :",i+1);

                           scanf("%d",&num[i]);

                           Class[i]=(int *)malloc(num[i]*sizeof(int));

             }

             for(i=0;i<cn;i++)

             {

                           for(j=0;j<num[i];j++)

                           {

                                        printf("%d반의 %d번 학생의 키:",i+1,j+1);

                                        scanf("%d",&Class[i][j]);

                                        printf("%d \n",Class[i][j]);

                           }

             }

}*/

/*         

             int i,j;//반,번

             int *l[2];//키

             int num[2];//학생수

             for(i=0;i<2;i++)

             {

                           printf("%d반의 학생수는?",i+1);

                           scanf("%d",&num[i]);

             }

             l[2]=(int *)malloc(num[2]*sizeof(int));

             for(i=0;i<2;i++)

             {

                           for(j=0;j<num[i];j++)

                           {

                                        printf("%d반 %d번의 키를 입력하세요.",i+1,j+1);

                                        scanf("%d",&l[i][j]);

                           }

             }

             for(i=0;i<2;i++)

             {

                           for(j=0;j<num[i];j++)

                           {

                                        printf("%d반 %d번의 키는 %dcm입니다.\n",i+1,j+1,l[i][j]);

                           }

             }

             free(l);

}*/

//숙제 : 완벽한 성적표 만들기 3학년까지 있음 1학년 1반 1번의 키를 입력 그리고 출력

#define grade 3

void main()

{

             int

}

/*

#include <stdio.h>

struct std

{

char name[128];

int kor;

int eng;

};

void main()

{

int i;

std s[5];