Armstrong numbers

A three-digit number is called an Armstrong number if the sum of the cube of its digits equals the number itself. For example, 153 is an Armstrong number because (\(1 ^ 3\)) + (\(5 ^ 3\)) + (\(3 ^ 3\)) = 153. Write all Armstrong numbers between 100 and 500.

To test your program consider these numbers, which are the only Armstrong numbers:

\[153=1^3+5^3+3^3\] \[370=3^3+7^3+0^3\] \[371=3^3+7^3+1^3\] \[407=4^3+0^3+7^3\]

Insist that the students test their programs by giving them the
expected outcome of their program.