C++ Program to Check Armstrong Number

In this tutorial, we will learn about Armstrong numbers in C++ i.e. how to write a program to check whether a number is Armstrong or not using C++.

Quick Info:💡

↪ An Armstrong number of a three-digit number is the sum of cubes of its digit is equal to the number itself.

For Example, 371=> 3³+7³+1³=27+343+1=371

                        153=> 1³+5³+3³ =1+125+27=153 …etc

↪ Here, we will write a code to check whether a number is armstrong or not and display its output on the output console.

Code to check armstrong number can be performed in two ways:

• Simple Method
• By Function

Check Armstrong Number Using Simple Method

Here’s a direct method to check an armstrong number.

Simply, the user will be asked to enter a three-digit positive integer then, the number is computed and displayed to a user.

Example:

#include<iostream.h>
#include<conio.h>
void main()
{
int num,sum=0,rem,temp;
cout<<"enter any three digits number:=";
cin>>num;
temp=num;
while(temp>0)
{
rem=temp%10;
temp=temp/10;
sum=sum+rem*rem*rem;
}
if(sum==num)
cout<<"Number is Armstrong";
else
cout<<"Number is not Armstrong";
getch();
}

//Output:
enter any three digits number:=371
Number is Armstrong

Working:

Flow of a program:

Check Armstrong Number Using Function

Functions are used to perform certain actions, and they are important for reusing code: Define the code once and use it many times.

And, this is a another method to check whether it is armstrong or not i.e. by function

Note: Always remember that execution starts from the main body only.

Example:

#include<iostream.h>
#include<conio.h>
int armstrong(int num)
{
int sum=0,rem,temp;
temp=num;
while(temp>0)
{
rem=temp%10;
temp=temp/10;
sum=sum+rem*rem*rem;
}
if(sum==num)
cout<<"Number is Armstrong";
else
cout<<"Number is not Armstrong";
return 0;
int main(){
int n;
cout<<"enter any three digits number:=";
cin>>n;
armstrong(n);
getch();
return 0;
}

//Output:
enter any three digits number:=153
Number is Armstrong

Working:

Flow of a program:

Well, I hope it really helped you to know C++ better.

Attention reader⚠ Don’t stop learning now.

Like Armstrong Number, check whether a number is a palindrome or not is also an important program in C++.

Just stay with us to get more such exciting codes to explore more in C++.