C++ Exercises: Check whether a given number is an Armstrong number or not

Last update on December 20 2024 12:24:37 (UTC/GMT +8 hours)

Write a C++ program to check whether a given number is an Armstrong number or not.

/*When the sum of the cube of the individual digits of a number
is equal to that number, the number is called Armstrong number. For example 153.
Sum of its divisor is 13 + 53;+ 33; = 1+125+27 = 153*/

Sample Solution:

C++ Code:

#include <iostream>
using namespace std;

int main()
{
    int num, r, sum = 0, temp;
    // Prompt user for input
    cout << "\n\n Check whether a given number is an Armstrong number or not :\n";
    cout << "-----------------------------------------------------------------\n";
    cout << " Input a number: ";
    cin >> num; // Input the number to check

    // Loop to calculate the sum of cubes of digits
    for (temp = num; num != 0; num = num / 10) 
    {
        r = num % 10; // Extract the digit
        sum = sum + (r * r * r); // Cube each digit and add to sum
    }

    // Check if the sum of cubes of digits equals the original number
    if (sum == temp)
        cout << temp << " is an Armstrong number." << endl; // Print if it's an Armstrong number
    else
        cout << temp << " is not an Armstrong number." << endl; // Print if it's not an Armstrong number
}

Sample Output:

Check whether a given number is an Armstrong number or not:                                                
 -------------------------------------------------------                                             
  Input a number: 153    
153 is an Armstrong number

Flowchart:

C++ Code Editor:

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