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Neon Number
  • Difficulty Level : Basic
  • Last Updated : 09 Nov, 2020

A neon number is a number where the sum of digits of square of the number is equal to the number. The task is to check and print neon numbers in a range.

Examples:

Input : 9
Output : Neon Number
Explanation: square is 9*9 = 81 and 
sum of the digits of the square is 9.

Input :12
Output : Not a Neon Number
Explanation: square is 12*12 = 144 and 
sum of the digits of the square is 9 (1 
+ 4 + 4) which is not equal to 12.

The implementation is simple, we first compute square of given number, the find sum of digits in the square.

C++




// C/C++ program to check and print
// Neon Numbers upto 10000
#include <iostream>
using namespace std;
#include <math.h>
  
int checkNeon(int x)
{
    // storing the square of x
    int sq = x * x;
  
    // calculating the sum of sum of digits
    // of sq
    int sum_digits = 0;
    while (sq != 0) {
        sum_digits = sum_digits + sq % 10;
        sq = sq / 10;
    }
    return (sum_digits == x);
}
  
// Driver Code
int main(void)
{
    // Printing Neon Numbers upto 10000
    for (int i = 1; i <= 10000; i++) 
        if (checkNeon(i))
            cout << i << " ";    
}


Java




// Java program to check and print
// Neon Numbers upto 10000
import java.io.*;
  
class GFG {
    // function to check Neon Number
    static boolean checkNeon(int x)
    {
        // storing the square of x
        int sq = x * x;
  
        // calculating the sum of sum of digits
        // of sq
        int sum_digits = 0;
        while (sq != 0) {
            sum_digits = sum_digits + sq % 10;
            sq = sq / 10;
        }
        return (sum_digits == x);
    }
  
    // Driver Code
    public static void main(String args[])
                        throws IOException
    {
        // Printing Neon Numbers upto 10000
        for (int i = 1; i <= 10000; i++) 
            if (checkNeon(i))
                System.out.print(i + " ");        
    }
}
// This code is contributed by Nikita Tiwari.


Python




# Python program to check and print 
# Neon Numbers upto 10000
  
# function to check Neon Number
def checkNeon (x) :
    # storing the square of x
    sq = x * x
      
    # calculating the sum of sum of digits
    # of sq
    sum_digits = 0
    while (sq != 0) :
        sum_digits = sum_digits + sq % 10
        sq = sq / 10
      
    return (sum_digits == x)
  
# Driver Code
  
i = 1
# Printing Neon Numbers upto 10000
while i <= 10000 :
    if (checkNeon(i)) :
        print i,
    i = i + 1
  
# This code is contributed by Nikita Tiwari.


C#




// C# program to check and print
// Neon Numbers upto 10000
using System;
  
class GFG 
{
    // function to check Neon Number
    static bool checkNeon(int x)
    {
        // storing the square of x
        int sq = x * x;
  
        // calculating the sum of sum of digits
        // of sq
        int sum_digits = 0;
        while (sq != 0) 
        {
            sum_digits = sum_digits + sq % 10;
            sq = sq / 10;
        }
        return (sum_digits == x);
    }
  
    // Driver Code
    public static void Main()
                          
    {
        // Printing Neon Numbers upto 10000
        for (int i = 1; i <= 10000; i++) 
            if (checkNeon(i))
                Console.Write(i + " "); 
    }
}
  
// This code is contributed by vt_m.


PHP




<?php
// PHP program to check and print
// Neon Numbers upto 10000
  
function checkNeon($x)
{
      
    // storing the square of x
    $sq = $x * $x;
  
    // calculating the sum of 
    // sum of digits of sq
    $sum_digits = 0;
    while ($sq != 0) 
    {
        $sum_digits = $sum_digits
                         $sq % 10;
        $sq = $sq / 10;
    }
    return ($sum_digits == $x);
}
  
    // Driver Code
    // Printing Neon Numbers
    // upto 10000
    for ($i = 1; $i <= 10000; $i++) 
        if (checkNeon($i))
            echo $i . " "
              
// This code is contributed by Sam007
?>



Output:

1 9


This article is contributed by Nikita Tiwari. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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