FASCINATING NUMBER

 FASCINATING NUMBER :
When a number( 3 digit or more) is multiplied by 2 and 3 ,and when both these products are concatenated with the original number all digits from 1 to 9 are present exactly once, regardless of the number of zeroes.


Example:Joining 192 with its products by 2 and 3, the resultant number is 192384576. This number contains all digits from 1 to 9 and these digits appear exactly once in the result. Hence 192 is a fascinating number. Note : The number should be of at least 3 digits to qualify for fascinating number test

/* program to find whether it is fascinating number or not*/

import java.util.*;
class FascinatingNumber
{
    boolean isUnique(String q)
    {
        int A[] = {0,0,0,0,0,0,0,0,0,0}; //to store frequency of every digit from '0' to '9'
        int i, flag = 0;
        char ch;
        for(i=0; i<q.length(); i++)
        {
            ch = q.charAt(i);
            A[ch-48]++;
            /*  increasing A[5] if ch='5' as '5'-48 = 53-48=5
             *  (ASCII values of '0' to '9' are 48 to 57) */
        }

        for(i=1; i<10; i++)
        {
            //checking if every digit from '1' to '9' are present exactly once or not
            if(A[i]!=1)
            {
                flag = 1; //flag is set to 1 if frequency is not 1
                break;
            }
        }

        if(flag == 1)
            return false;
        else
            return true;
    }
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        FascinatingNumber ob = new FascinatingNumber();

        System.out.print("Enter a number : ");
        int n = sc.nextInt();
        String p = Integer.toString(n); //converting the number to String

        if(p.length()<3)
            System.out.println("Number should be of atleast 3 digits.");

        else
        {
            String s = Integer.toString(n*1) + Integer.toString(n*2) + Integer.toString(n*3);
            /*  Joining the first, second and third multiple of the number
             *  by converting them to Strings and concatenating them*/
            if(ob.isUnique(s))
                System.out.println(n+" is a Fascinating Number.");
            else
                System.out.println(n+" is not a Fascinating Number.");
        }    
    }
}






OUTPUT:

Enter a number : 192

192 is a Fascinating Number.

Enter a number : 152
152 is not a Fascinating Number.