Example: C program to display armstrong number between two intervals using user defined function

// C program to display armstrong number between two intervals using user defined function
#include <stdio.h>
#include <math.h>

// @custom function to find the armstrong numbers
int findArmstrongNumbers(int low_number, int high_number) {
    int original_number, remind, count = 0, temp;
    double result = 0.0;

    // this will swap the value of intervals between each other
    // if low_number is greater then high_number
    if (low_number > high_number) {
        temp;
        temp = low_number;
        low_number = high_number;
        high_number = temp;
    }

    printf("\nArmstrong numbers between %d and %d is: ", low_number, high_number);

    for (int i = low_number + 1; i < high_number; i++) {
        original_number = i;

        // first it will count digits of numbers
        while (original_number != 0) {
            original_number = original_number/10;
            count++;
        }

        original_number = i;

        // second it will contains sum of nth power of individual digits
        while (original_number != 0) {
            remind = original_number % 10;
            result += pow(remind, count);
            original_number = original_number/10;
        }

        // third it will check if number is equal to the sum of nth power of individual digits
        if ((int)result == i) {
            printf("%d ", i);
        }

        // last it will reset the values of count & result
        count = 0;
        result = 0;
    }
    printf("\n");
    return 0;
}

// @driver function to call & find the armstrong numbers
int main() {
    int low_number, high_number;

    printf("Enter the two intervals:\n");
    scanf("%d %d", &low_number, &high_number);

    // @call the custom function to find the armstrong numbers
    findArmstrongNumbers(low_number, high_number);

    return 0;
}