Modified Kaprekar Numbers Hacker Rank Solution in C

 in modified kaprekar number, say x

let number of digits in x, say nd

let square = x*x

then 

x = square/10^nd + square%(10^nd) then x would be a modified kaprekar number

https://www.hackerrank.com/challenges/kaprekar-numbers/problem

#include<stdio.h>

#include<math.h>

int main() 

{

    long int n,m,r,f;

    int flag = 0;

    scanf("%ld%ld",&n,&m);

    for(long int i=n;i<=m;i++)

    {

        long int sum;

        long int a = log10(i)+1;

        

       long int p = i * i;

        long int g = pow(10,a);

        sum = p%g + p/g;

        if(sum == i)

        {

            printf("%ld ",sum);

            flag++;

        }

    }

    if(flag == 0)

        printf("INVALID RANGE");       

    return 0;

}