❮ C Exercise Example75 C Examples Output Array ❯

C Language Example - Check Armstrong Number (Armstrong Number)

C Language Examples

An Armstrong number is a number that is equal to the sum of its own digits each raised to the power of the number of digits. For example:

153 = 1^3 + 5^3 + 3^3
1634 = 1^4 + 6^4 + 3^4 + 4^4

Example

#include <stdio.h>
int main()
{
    int number, originalNumber, remainder, result = 0;

    printf("Enter a three-digit number: ");
    scanf("%d", &number);

    originalNumber = number;

    while (originalNumber != 0)
    {
        remainder = originalNumber % 10;
        result += remainder * remainder * remainder;
        originalNumber /= 10;
    }

    if (result == number)
        printf("%d is an Armstrong number", number);
    else
        printf("%d is not an Armstrong number", number);

    return 0;
}

Output:

Enter a three-digit number: 371
371 is an Armstrong number

Example - Armstrong Numbers Between Two Integers

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

int main()
{
    int low, high, i, temp1, temp2, remainder, n = 0, result = 0;

    printf("Enter two integers: ");
    scanf("%d %d", &low, &high);
    printf("Armstrong numbers between %d and %d are: ", low, high);

    for (i = low + 1; i < high; ++i)
    {
        temp2 = i;
        temp1 = i;

        // Calculate the number of digits
        while (temp1 != 0)
        {
            temp1 /= 10;
            ++n;
        }

        while (temp2 != 0)
        {
            remainder = temp2 % 10;
            result += pow(remainder, n);
            temp2 /= 10;
        }

        if (result == i) {
            printf("%d ", i);
        }

        n = 0;
        result = 0;

    }
    return 0;
}

Output:

Enter two integers: 100 1000
Armstrong numbers between 100 and 1000 are: 153 370 371 407

Example - Check Armstrong Number Using a Function

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

int checkPrimeNumber(int n);
int checkArmstrongNumber(int n);

int main()
{
    int n, flag;

    printf("Enter a positive integer: ");
    scanf("%d", &n);

    // Check for prime number
    flag = checkPrimeNumber(n);
    if (flag == 1)
        printf("%d is a prime number.\n", n);
    else
        printf("%d is not a prime number.\n", n);

    // Check for Armstrong number
    flag = checkArmstrongNumber(n);
    if (flag == 1)
        printf("%d is an Armstrong number.", n);
    else
        printf("%d is not an Armstrong number.", n);
    return 0;
}

int checkPrimeNumber(int n)
{
    int i, flag = 1;

    for (i = 2; i <= n / 2; ++i)
    {
        // Condition for non-prime number
        if (n % i == 0)
        {
            flag = 0;
            break;
        }
    }
    return flag;
}

int checkArmstrongNumber(int number)
{
    int originalNumber, remainder, result = 0, n = 0, flag;

    originalNumber = number;

    while (originalNumber != 0)
    {
        originalNumber /= 10;
        ++n;
    }

    originalNumber = number;

    while (originalNumber != 0)
    {
        remainder = originalNumber % 10;
        result += pow(remainder, n);
        originalNumber /= 10;
    }

    // Check condition
    if (result == number)
        flag = 1;
    else
        flag = 0;

    return flag;
}

Output:

Enter a positive integer: 371
371 is not a prime number.
371 is an Armstrong number.

C Language Examples

❮ C Exercise Example75 C Examples Output Array ❯