Program to find out Primorial(P#) of a number

PROGRAM

Primorial(P#) is defined to be the product of prime numbers less than or equal to P. e.g.

3# = 2*3=6

5# = 2*3*5=30

13# = 2*3*5*7*11*13=30030

This is also called p-prime-factorial.

WAP to input a number and print its primordial i.e. n#

SAMPLE DATA

Enter a number=13

13#=2*3*5*7*11*13=30030

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/**

 * class primorial finds the primorial of a given number.

 * @author: Nitendra Kumar

 * @version: June 4/2013

 */

import java.util.Scanner;

public class primorial

{

  public int num=0;

  public void getnum()  //method to accept number from user

  {

      Scanner in=new Scanner(System.in);  //creating object of Scanner class

      System.out.println("Enter a number");

      num=in.nextInt();

    }

    public void findprimorial()  //method to find out primorial

    {

        int res=2,flag=0;

        String str="2";

        for(int i=3;i<=num;i++)

        {

         flag=0;

        for(int j=2;j<i;j++)

        {

           if(i%j==0)

            {

                flag=1;

                break;

            }

        }

        if(flag!=1)

        {

        res*=i;

        str=str+ "*" +i;      

        }

    }

       System.out.println(num +"#= " +str +"=" +res);

    }

    

    public static void main()

    {

        primorial ob=new primorial();  //creating object of primorial class

        ob.getnum();                   //calling method

        ob.findprimorial();            //calling method

    }

   

}

OUTPUT:

Enter a number

13

13#= 2*3*5*7*11*13=30030

/*---------------Program developed by: Nitendra Kumar---------------*/

//For more details visit http://javawithnitendra.blogspot.in