The Program inC++ Program to find Armstrong number for Given range are given below:

#include <iostream>
#include <cmath>

using namespace std;

int number_of_digits(int n) {
    int count = 0;
    while (n != 0) {
        count++;
        n /= 10;
    }
    return count;
}

bool is_Armstrong(int n) {
    int num_of_digits = number_of_digits(n);
    int sum = 0;
    int original_num = n;
    while (n != 0) {
        int digit = n % 10;
        sum += pow(digit, num_of_digits);
        n /= 10;
    }
    return original_num == sum;
}

int main() {
    int start, end;
    cout << "Hello Codeauri Family,Enter the start and end of the range to find the Armstrong number here: ";
    cin >> start >> end;
    cout << "Okay, the Armstrong numbers in the given range are: " << endl;
    for (int i = start; i <= end; i++) {
        if (is_Armstrong(i)) {
            cout << i << " ";
        }
    }
    cout << endl;
    return 0;
}

Output:

Hello Codeauri Family,Enter the start and end of the range to find the Armstrong number here: 11
1000
Okay, the Armstrong numbers in the given range are:
153 370 371 407

Pro-Tips💡

The program defines two functions, number_of_digits and is_Armstrong.

The number_of_digits function takes an integer n as input and returns the number of digits in n.

The is_Armstrong function takes an integer n as input and returns a Boolean indicating whether n is an Armstrong number or not. It does this by finding the number of digits in n,

and then repeatedly dividing n by 10 and summing the result of each digit raised to the power of the number of digits.

In the main function, the program prompts the user to enter the start and end of the range, and stores the input in the start and end variables.

Then it iterates over the numbers in the given range, and for each number, it calls the is_Armstrong function to determine if it is an Armstrong number.

If it is, it is printed to the screen.