Armstrong Number

An Armstrong number, also called a narcissistic number, equals the sum of its digits each raised to the power of the digit count. 153 has 3 digits, and 1³ + 5³ + 3³ = 153.

Solve it in two passes, or one if you convert to a string:

1. count the digits k
2. peel each digit and add digit^k

Then compare the total against the original value. A classic bug is comparing against n after you've already divided it down to 0, so save a copy first.