C Exercises: Generate and show all Kaprekar numbers less than 1000

C Numbers: Exercise-7 with Solution

Write a program in C to generate and show all Kaprekar numbers less than 1000.

Sample Solution:

C Code:

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

// Function to check if a number is a Kaprekar number
bool chkkaprekar(int n)
{
    if (n == 1)
       return true; // If the number is 1, it's considered a Kaprekar number

    int sqr_n = n * n; // Square of the number
    int ctr_digits = 0; // Counter for the number of digits in the square

    // Count the number of digits in the square of the number
    while (sqr_n)
    {
        ctr_digits++;
        sqr_n /= 10;
    }

    sqr_n = n * n; // Reset the square of the number

    // Loop to check for Kaprekar property
    for (int r_digits = 1; r_digits < ctr_digits; r_digits++)
    {
         int eq_parts = pow(10, r_digits); // Calculate the divisor for splitting the square

         if (eq_parts == n)
            continue; // Skip when the divisor equals the number itself

         // Calculate the sum of the split parts of the square
         int sum = sqr_n / eq_parts + sqr_n % eq_parts;

         if (sum == n)
           return true; // If the sum of split parts equals the number, it's a Kaprekar number
    }
    return false; // If the conditions aren't met, it's not a Kaprekar number
}

// Main function
int main()
{
    printf("\n\n Generate and show all Kaprekar numbers less than 1000: \n");
    printf(" -----------------------------------------------------------\n");
    printf(" The Kaprekar numbers less than 1000 are: \n");

    // Loop to check Kaprekar numbers less than 1000
    for (int i = 1; i < 1000; i++)
    {
        if (chkkaprekar(i)) // Check if 'i' is a Kaprekar number
        {
            printf("%d ", i); // Print 'i' if it's a Kaprekar number
        }
    }

    printf("\n");
    return 0;
}

Sample Output:

 The Kaprekar numbers less than 1000 are:                                                                     
1 9 45 55 99 297 703 999 

Visual Presentation:

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