Program 3- Program to find if the number is prime or composite.

This program takes in an integer num1 as a screen input from the user.
It then determines whether the integer is prime or composite.
It finally outputs the approriate message by writing to the 'cout' stream.

#include <iostream.h>
#include <conio.h>
#include <process.h>

void main()
{
            clrscr();
            int num1,x;
            cout << "Enter an integer : " << endl;
            cin>>num1;
            for(x=2;x<num1;x++)
                 {
                      if(num1%x==0)

                          {
                             cout << num1 << " is a composite number." << endl;
                           }

                      else
                          {
                             cout << num1 << " is a prime number." << endl;                                            
                           }
                      }

 getch();
 exit(0);
}

Sample Input:

21

Sample Output:

21 is a composite number.