Unlock the Secret of Armstrong Numbers

The Magic of Armstrong Numbers

A positive integer is considered an Armstrong number of order n if the sum of the cubes of its individual digits is equal to the number itself. Sounds intriguing, doesn’t it? Let’s take a closer look.

The 3-Digit Armstrong Number

In the case of a 3-digit Armstrong number, the sum of the cubes of each digit must equal the number itself. For instance, 153 is an Armstrong number because 1³ + 5³ + 3³ = 153.

int num = 153;
int sum = 0;
while (num!= 0) {
    int digit = num % 10;
    sum += pow(digit, 3);
    num /= 10;
}
if (sum == 153) {
    cout << "153 is an Armstrong number." << endl;
}

Scaling Up to n Digits

But what if we want to check Armstrong numbers with more than 3 digits? We can modify our program to calculate the number of digits in the entered number and store it in a variable n. Then, we use the pow() function to compute the power of individual digits in each iteration of the while loop.

int num, n;
cout << "Enter a number: ";
cin >> num;
n = to_string(num).length();
int sum = 0;
int temp = num;
while (temp!= 0) {
    int digit = temp % 10;
    sum += pow(digit, n);
    temp /= 10;
}
if (sum == num) {
    cout << num << " is an Armstrong number." << endl;
} else {
    cout << num << " is not an Armstrong number." << endl;
}

Taking it to the Next Level

Now that you’ve mastered the art of checking Armstrong numbers, why not take it a step further? Try writing a program to display Armstrong numbers between two intervals. The possibilities are endless!

• Write a program to find Armstrong numbers between 100 and 999.
• Modify the program to work with different intervals.
• Explore other properties of Armstrong numbers.

Get Ready to Code

With these concepts under your belt, you’re ready to dive into the world of C++ programming and create your own Armstrong number-checking program. So, what are you waiting for? Start coding today!

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