Question

write a program to find neon number between 10 to 10000 in Java

Answer 1

/* To check whether a number is 'Neon'. */
/* A number is said to be Neon if the sum of digits of square of the given number is equal to the number itself */


import java.io.*;

public class Neon_Number
{
    public static void main(String args[]) throws IOException
    {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        
        long n,s,d,sum;
        int f=1;
        
        System.out.println(" A number is said to be 'Neon' if the sum of digits of square of the given number is equal to the number itself ");
        System.out.println(" There are only three Neon numbers: 0, 1 and 9 .");
        System.out.println();
        
        while (f==1)
        {
            sum=0;
            System.out.print("Enter a number: ");
            n = Long.parseLong(in.readLine());
            
            s=n*n;
           
            
            do
            {
                d=s%10;
                sum+=d;
                s=s/10;
            }
            while(s!=0);
            
            if (sum==n)
            System.out.println(n+" is a Neon number");
            else
            System.out.println(n+" is not a Neon number");
            
            System.out.println();
            System.out.print("Enter 1 to repeat, 0 to exit: ");
            f = Integer.parseInt(in.readLine());
            System.out.println();
        }
        
        System.out.println();
        System.out.println("Program ends.");
    }
}
        
        
       

Answer 2

class Neon
{
//program to check whether the number is neon or not
int sq,d,sd=0;
System.out.println ("the neon numbers are ");
for(int i=10;i <=10000;i++)
{
sq=i*i;
while (sq!=0)
{
d=sq%10
sd = sd+d;
sq/=10;
}
if (sd==i)
{
System.out.println(i+" , ");
}
sd=0;
}//for loop closed
}//main
}

variable description for convenience :-
__________________________________

i - as a loop variable for numbers from
10 to 1000.

sq = to store the value of square of numbers

d = for the digits of the square

sd = sum of the digits of square