Given number is z , determine whether this number is Armstrong Number or not. A positive integer number of n digits is called an Armstrong Number of order n if
abcd…=pow(a,n) + pow(b, n) +pow(c,n)+pow(d,n)+………, where a, b, c, d are digits of input number abcd….., n is the number of digits present in the number.
Approach
- First count the number of digits present in the given number z. Let the number of digits be n.
- For every digits present in the number z ,let digits are d1 , d2 , d3,…..;compute d1^n , d2^n , d3^n……..
- If the sum of all computed digits are equal to z i.e. d1^n+d2^n+d3^n+……..=z; it is an armstrong number, then print that this number is an armstrong number, else print this number is not an armstrong number.
Example:
153 is an armstrong number because
1^3+5^3+3^3=153
1634 is a 4 digit armstrong number because
1^4+6^4+3^4+4^4=1634
Java Program to check a number is Armstrong Number Or Not
public class ArmstrongNumber {
public static void main (String args[]) {
// code to enter a number you want to check armstrong number or not
Scanner sc = new Scanner(System.in);
System.out.println(“Enter the number you want to check whether armstrong number or not”);
int n = sc.nextInt();
int temp=n,digits=0,rev,sum=0;
//To find the number of digits:
while(temp>0) {
temp=temp/10;
digits++;
}
temp=n;
while (temp > 0) {
//To find the last digit
rem=temp%10;
//Sum up of the each digit to the power total number of digits present in the number
sum + = Math.pow(rem,digits);
//To remove the last digit
temp=temp/10;
}
if (sum==n) {
System.out.println(“The given number is an armstrong number”);
}
else
System.out.println(“The given number is not an armstrong number”);
}
}
}
If you don’t understand how to find the number of digits java program and how to sum up each digits of a number,
Check the following :
Java Program to count the number of digits in a given number