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Program to find Armstrong numbers in given range

Program to find Armstrong numbers in given range

What is Armstrong number?

An Armstrong number is a n-digit number that is equal to the sum of nth power of its digits. For example,
371 = 3^3 + 7^3 + 1^3 = 371
407 = 4^3 + 0^3 + 7^3 = 407

Logic to find all Armstrong number between 1 to n

    Input upper limit to print Armstrong number from user. Store it in some variable say end.
    Run a loop from 1 to end, increment 1 in each iteration. The loop structure should look like for(i=1; i<=end; i++).
    Inside the loop print current number i, if it is Armstrong number.

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

int main()
{
    int j, lastDigit, digits, sum, i;
    int start, end;

    /* Input lower and upper limit from user */
    printf("Enter lower limit: ");
    scanf("%d", &start);
    printf("Enter upper limit: ");
    scanf("%d", &end);

    printf("Armstrong number between %d to %d are: \n", start, end);

    for(i=start; i<=end; i++)
    {
        sum = 0;

        /* Copy the value of j for processing */
        j = i;

        /* Find total digits in j */
        digits = (int) log10(j) + 1;

        /* Calculate sum of power of digits */
        while(j > 0)
        {
            /* Extract the last digit */
            lastDigit = j % 10;

            /* Find sum of power of digits */
            sum = sum + pow(lastDigit, digits);

            /* Remove the last digit */
            j = j / 10;
        }

        /* Check for Armstrong number */
        if(i == sum)
        {
            printf("%d, ", i);
        }
    }

    return 0;
}