C++ Programming Basics

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Armstrong number

C++ Programming Basics Basic code examples Armstrong number

An Armstrong number (also called a plus perfect number or narcissistic number) is a number equal to the sum of the nth power of the digits, where n is the quantity of digits in the number.

Check Armstrong Number

#include <iostream>
using namespace std;

bool checkArmstrong(int number) {
    int temp, remainder, i, counter = 0, result = 0, power;
    temp = number;

    while (temp != 0) {
        temp /= 10;
        counter++;
    }
    temp = number;

    while (temp != 0) {
        remainder = temp % 10;

        power = 1;
        i = counter;
        while (i != 0) {
            power *= remainder;
            i--;
        }

        result += power;
        temp /= 10;
    }
    
    if (number == result) {
        return true;
    } else {
        return false;
    }
}

int main() {
    int number;

    cout << "Enter a number to check for armstrong:  ";
    cin >> number;

    if (checkArmstrong(number)) {
        cout << number << " is an armstrong number";
    } else {
        cout << number << " is not an armstrong number";
    }

    return 0;
}
Output
Enter a number to check for armstrong:  371
371 is an armstrong number

Armstrong Number Series

#include &lt;iostream&gt;
using namespace std;

bool checkArmstrong(int number) {
    int temp, remainder, i, counter = 0, result = 0, power;
    temp = number;

    while (temp != 0) {
        temp /= 10;
        counter++;
    }
    temp = number;

    while (temp != 0) {
        remainder = temp % 10;

        power = 1;
        i = counter;
        while (i != 0) {
            power *= remainder;
            i--;
        }

        result += power;
        temp /= 10;
    }

    if (number == result) {
        return true;
    } else {
        return false;
    }
}

int main() {
    int max;

    cout << "Enter the upper bound to find armstrong numbers: ";
    cin >> max;

    cout << "Armstrong Number Series:";
    for (int i = 1; i <= max; i++) {
        if (checkArmstrong(i)) {
            cout << i << " ";
        }
    }

    return 0;
}
Output
Enter the upper bound to find armstrong numbers: 1000
Armstrong Number Series:1 2 3 4 5 6 7 8 9 153 370 371 407
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