How to Find Armstrong Numbers between two given Integers

An integer is referred to as the Armstrong numbers of the order n. When it's each digit is separated, cubed, and added together then it will result in a sum that is the same as the number, (i.e., pqrs... = pⁿ + qⁿ + rⁿ + sⁿ +...).

If there is an Armstrong number with three digits, the total of cubes in each number is equal to the number in itself.

Example:

371 = 3 * 3 * 3 + 7 * 7 * 7 + 1 * 1 * 1  
    = 27 + 343 + 1
    = 371        
Therefore, 371 is an Armstrong number.

In this tutorial, we will learn how we can find Armstrong numbers between two given integers by using Python language.

For example:

Input: Two Integer Numbers: 1000 10000
Output: Armstrong Numbers Between Two Given Integers: 1634 8208 9474
Explanation: For the Output numbers: 1000 and 10000 are given two integers. (interval)
  1634 = 1 * 1 * 1 * 1 + 6 * 6 * 6 * 6 + 3 * 3 * 3 * 3 + 4 * 4 * 4 *4  
      = 1 + 1296 + 81 + 256
      = 1634
  8208 = 8 * 8 * 8 * 8 + 2 * 2 * 2 * 2 + 0 * 0 * 0 * 0 + 8 * 8 * 8 * 8  
      = 4096 + 16 + 0 + 4096
      = 8206
  9474 = 9 * 9 * 9 * 9 + 4 * 4 * 4 *4 + 7 * 7 * 7 * 7 + 4 * 4 * 4 *4
      = 6561 + 256 + 2401 + 256 
      = 9474

The method we use below is easy. We look through all numbers within the range. For each number, we first determine the number of digits within it. Make the total number of decimal digits of the current number be the number "n". Then we calculate the sum of the" n-th" power of each digit. If the sum is greater than "K", then we record the result.

Code:

# First we will import required module:
import math
lower1 = int(input("Please enter the lower range of the integer: "))
upper1 = int(input("Please enter the upper range of the integer: "))
print("The Armstrong Numbers Between Two Given Integers:")
for num_1 in range(lower1, upper1 + 1):

   # Now, we will set the order of number
   order1 = len(str(num_1))
    
   # here, we are initializing sum
   sum = 0

   temp1 = num_1
   while temp1 > 0:
       digit1 = temp1 % 10
       sum += digit1 ** order1
       temp1 //= 10

   if num_1 == sum:

       print(num_1)

Output:

Please enter the lower range of the integer:  1000
Please enter the upper range of the integer:  10000
The Armstrong Numbers Between Two Given Integers:
1634
8208
9474