/* A kaprekar number is a number in base 10 whose square can be split such that the the sum of those numbers

add up to the original number for eg : (45)^2 = 2025 => 20+25=45 */

# include <stdio.h>

# include <string.h>

# include <stdbool.h>

# include <math.h>

bool iskaprekarnum(int n)

{

if (n == 1) // If the number passed is 1 then it is also considered to be a kaprekar number

return true;

int square_number = n * n; // Finding the square

int count_digits = 0; //This will be the counter variable for the number of digits in the number

while (square_number != 0)

{

count_digits++;

square_number /= 10;

}

square_number = n*n; // Recalculating square as it was changed in the above while loop

for (int r_digits=1; r_digits<count_digits; r_digits++)

{

int equal_parts = (int) pow(10, r_digits); //Type casting to integer value

if (equal_parts == n)

continue;

int sum = square_number/equal_parts + square_number % equal_parts;

if (sum == n)

return true;

}

return false;

}

int main()

{ int num;

printf("Enter the number till which you want to print the kaprekar numbers");

scanf("%d",&num);

for (int i=1; i<num; i++) {

if (iskaprekarnum(i)) //Checking if the number is a kaprekar number or not

printf("%d ",i );

}

return 0;

}