C Exercises: Check whether a given number is a Kaprekar number or not

C Numbers: Exercise-6 with Solution

Write a program in C to check whether a given number is a Kaprekar number or not.

Test Data
Input a number: 45

Sample Solution:

C Code:

# include <stdio.h>
# include <stdbool.h>
# include <math.h>

bool chkkaprekar(int n)
{
    if (n == 1)
       return true;
    int sqr_n = n * n;
    int ctr_digits = 0;
    while (sqr_n)
    {
        ctr_digits++;
        sqr_n /= 10;
    }
    sqr_n = n*n; 
    for (int r_digits=1; r_digits<ctr_digits; r_digits++)
    {
         int eq_parts = pow(10, r_digits);

         if (eq_parts == n)
            continue;
         int sum = sqr_n/eq_parts + sqr_n % eq_parts;
         if (sum == n)
           return true;
    }
    return false;
}
int main()
{
int kpno;
  printf("\n\n Check whether a given number is a Kaprekar number: \n");
  printf(" -------------------------------------------------------\n");
  printf(" Input a number: ");
  scanf("%d",&kpno);
		  if (chkkaprekar(kpno)==true)
		  {
		   printf("%d is a Kaprekar number. \n",kpno);
		  }
		  else
		  {
		   printf("%d is not a Kaprekar number. \n",kpno);
		  }
}

Sample Output:

 Input a number: 45                                                                                           
45 is a Kaprekar number. 

Pictorial Presentation:

Flowchart:

C Programming Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a program in C to find the Deficient numbers (integers) between 1 to 100.
Next: Write a program in C to generate and show all Kaprekar numbers less than 1000.