C++ Program to Check Armstrong Number
Armstrong Number
Armstrong number is a number that is equal to the sum of the
cubes of its digits. For example, 0, 1, 153, 370, 371 and 407 are the Armstrong
numbers. Let's try to understand why 153 is an Armstrong number. Let’s take a
look at example.
Logic to check Armstrong Number
- Count number of digits in a number (entered by user)
- Make a new number which is equal to the sum of the cube of its digits.
- Check if the previous number is equal to the new number then it is Armstrong Number.
Write a program to check that the number (entered by user) is Armstrong
number or not?
// C++ Program to check Armstrong Number
#include <iostream>
#include <conio.h>
#include <math.h>
using namespace std;
int main() {
int
num,copy,n=0,rem,ans=0;
cout<<"Enter
Any Number: ";
cin>>num;
copy=num;
//
while loop to count number of digits
while(copy!=0)
{
copy/=10;
n++;
}
copy=num;
//
while loop to make new number (ans)
while(copy!=0)
{
rem=copy%10;
ans=ans+pow(rem,n);
copy/=10;
}
// if
else statement to compare previous number with new number
if(ans==num)
cout << num << " is an Armstrong Number.";
else
cout << num << " is not an Armstrong Number.";
_getch();
}
Output
Enter
Any Number: 153
153 is an Armstrong
Number.
Enter
Any Number: 456
456 is not an Armstrong
Number.
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