Unleashing the Power of C Programming: A Deeper Dive into User-Defined Functions

The Problem Statement

Given a number, how can we determine if it’s prime and Armstrong? A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. An Armstrong number, on the other hand, is a number that is equal to the sum of its own digits each raised to the power of the number of digits.

The Solution: User-Defined Functions to the Rescue

To tackle this problem, we’ll create two user-defined functions: checkPrimeNumber() and checkArmstrongNumber(). These functions will take an integer as input and return 1 if the number meets the respective criteria, and 0 otherwise.

Function Breakdown

Let’s dissect the checkPrimeNumber() function:

int checkPrimeNumber(int num) {
    int flag = 1;
    for (int i = 2; i * i <= num; i++) {
        if (num % i == 0) {
            flag = 0;
            break;
        }
    }
    return flag;
}

The checkArmstrongNumber() function follows a similar structure:

int checkArmstrongNumber(int num) {
    int sum = 0, temp = num;
    int digits = 0;
    while (temp!= 0) {
        digits++;
        temp /= 10;
    }
    temp = num;
    while (temp!= 0) {
        int digit = temp % 10;
        sum += pow(digit, digits);
        temp /= 10;
    }
    return sum == num? 1 : 0;
}

Putting it all Together

In the main() function, we prompt the user to enter a number:

int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);
    int isPrime = checkPrimeNumber(num);
    int isArmstrong = checkArmstrongNumber(num);
    if (isPrime && isArmstrong) {
        printf("%d is both prime and Armstrong.\n", num);
    } else if (isPrime) {
        printf("%d is prime but not Armstrong.\n", num);
    } else if (isArmstrong) {
        printf("%d is Armstrong but not prime.\n", num);
    } else {
        printf("%d is neither prime nor Armstrong.\n", num);
    }
    return 0;
}

The Power of User-Defined Functions

By creating these two functions, we’ve not only solved the problem but also demonstrated the flexibility and reusability of user-defined functions in C programming. By encapsulating complex logic within functions, we can write more efficient, modular, and maintainable code.

Some key benefits of using user-defined functions include:

• Modularity: Breaking down complex code into smaller, manageable functions makes it easier to understand and maintain.
• Reusability: Functions can be called multiple times within a program, reducing code duplication and increasing efficiency.
• Readability: Well-named functions and clear documentation make the code more readable and easier to understand.