An Armstrong number is an n -digit number that is equal to the sum of the n th powers of its digits. For example 153 is an Armstrong Number in 3 digit number 1 3 + 5 3 + 3 3 = 153 1 +125+27 =153 1634 is an Armstrong Number in 4 digit number 1 4 + 6 4 + 3 4 + 4 4 = 1634 1+1296+81+256=1634 And so numbers from 0-9 all are Armstrong Numbers as 0 1 is 0 , 1 1 is 1, 2 1 is 2 , 3 1 is 3 and so on.. Armstrong Algorithm Step1: Read a number. Step2: Store all the digits of a number in an array digits[] Step3: Count all the digits of a number and store in variable length Step4: Start a loop till the length of a number Step5: Raise each digit to a power equal to the number of digits in the number. For ex, each digit of a three‑digit number would be raised to the third power; each digit of a Seven‑digit number would be raised to the Seventh power; and so on Step6: Add the results to variable sum