Magic Number

 Magic number is the if the sum of its digits recursively are calculated till a single digit If the single digit is 1 then the number is a magic number. Magic number is very similar with Happy Number. 2+2+6=10 sum of digits is 10 then again 1+0=1 now we get a single digit number is 1.

import java.util.*;

class magic

{ //class magic opens

    public static void main(String[]args)

    { //main method opens

        Scanner sc=new Scanner(System.in);

        System.out.println("Enter a no");

        int n=sc.nextInt();//variable n to accept the no

        int r=0,sum=0,k=0;//variable r to extract the digits,variable sum and k to store the sum

        sum=n;

        while(sum>9)

        {

            k=sum;

            sum=0;

            while(k>0)

            {

                r=k%10;

                sum=sum+r;

                k=k/10;

            }

        }

        if(sum==1)

        System.out.println(n+" is a magic no");

        else

        System.out.println(n+" is not a magic no");

    }//main method closes

}//class closes