This post about C and C++ programs to display all Armstrong numbers less than 1000. But before all, I should tell what an Armstrong number is. An Armstrong number is a number that is the sum of its own digits each raised to the power of the number of digits. Consider an example. 153 is an Armstrong number. Since it is a 3 digit number, to check whether it is an Armstrong number or not, we should add the 3rd power of each digit. So, in the program, we should have a code to determine number digits in number, then add the n
th powers (where n is the number of digits) of each digit in the number and check whether both the sum and original number are the same.
C Program:
#include<stdio.h>
#include<math.h>
void main()
{
int n,sum,r,digits;
for(n=1;n<=1000;n++)
{
digits=0;
r=n;
sum=0;
while(r!=0) //Counting Digits
{
digits++;
r/=10;
}
r=n;
while(r!=0) /*Adding Digits Raised To a Power That Is Equal To Number of Digits */
{
sum+=pow((r%10),digits);
r=r/10;
}
if(sum==n)
{
printf("%5d",sum);
}
}
}
C++ Program:
