first lab class object oriented programming with c++

// first lab class object oriented programming with c++ .                                md.jahangir alam (polas)
// write a program to display student information :roll,name,dept                 date:17/1/2011
#include<iostream.h>
#include<conio.h>
    class diu{
        int roll;
        char name[30];
        char dept[20];
        public:
     void getinput();
     void display();
    };

 void diu::getinput(){
        cin>>roll>>name>>dept;
    }
    void diu::display(){
        cout<<name<<endl<<roll<<endl<<dept;
    }
void main(){
        clrscr();
        diu cse;
        cse.getinput();
        cse.display();
        getch();
    }

use funcation calling : give two input and see output
addition sub multi divi remin .
#include<stdio.h>
int add(int a,int b);
int sub(int a,int b);
int multi(int a,int b);
int divi(int a,int b);
int remain(int a,int b);
int main()
{
 int  a,b;
 printf("enter two int number:\n");
 scanf("%d %d",&a,&b);
add(a,b);
  sub(a,b);
  multi(a, b);
  divi(a, b);
 remain( a,b);
 }
/*2 int addition*/
int add(int a,int b)
{
int c;

    c=a+b;
        printf("\n%d",c);
    return 0;
}
/*2 int sub*/
int sub(int a,int b)
{
int c;

    c=a-b;
    printf("\n%d",c);
   return 0;

}
/*2 int multi*/
int multi(int a,int b)
{

int c;
    c=a*b;
    printf("\n%d",c);
    return 0;

}
/*2 int division*/
int divi(int a,int b)
{
int c;

    c=a/b;
    printf("\n%d",c);return 0;

}
//2 int remainder//
int remain(int a,int b)

{

int c;
    c=a%b;
    printf("\n%d",c);
    return 0;
}

/*programming class problem:take a number from user
and find out the following characteristies:
1.positive or negative number?
2. even or odd numer?
3.divisible by 2?
4.leap year?
*/
#include<stdio.h>
int positive(int num);
int even_odd(int num);
int divisible(int num);
int leapyear(int num);
int main()
{
int num;
  printf("Sample input:");
  scanf("%d",&num);
  printf("\n\nsample output:\n");
  positive( num);
  even_odd( num);
  divisible( num);
  leapyear( num);
}
int positive(int num)
{
if(num>0)
  printf("\n%d is positive num.",num);
else
  printf("\n%d is negative num.",num);
return 0;
}
int even_odd(int num)
{
if(num%2==0)
  printf("\n%d is even num.",num);
else
  printf("\n%d is odd num.",num);
return 0;
}
int divisible(int num)
{

if(num%2==0)
  printf("\n%d is a divisible by 2. ",num);

else
  printf("\n%d is  a not divisible by 2. ",num);

return 0;
}
int leapyear(int num)
{
if(num%4==0&&num%100!=0||num%400==0)
  printf("\n%d is a leap year .",num);
else
  printf("\n%d is not leap year.",num);
return 0;
}