StealthyCoder

This first part will deal with setting up the problem and the first initial code.

Problem

The problem to solve is to find the first x amount of Narcissistic Numbers . What they are is easy to explain. The process by which to identify if a number is narcissistic is by following these steps:

• Separate number into individual numerals
• Raise each numeral to the power that is equal to the total amount of numerals (length of the number)
• Sum those results together
• If that sum is equal to the original number then it is narcissistic

A quick example is 153 .

1. Separate numerals are 1, 5 and 3.
2. 1 ** 3 = 1, 5 ** 3 = 125 and 3 ** 3 = 27
3. 1 + 125 + 27 = 153
4. 153 == 153 is true

Therefore 153 is narcissistic. By looking at this algorithm we can see that all numbers with length 1 are narcissistic. Since something to the power of 1 is itself.

Naive code

The naive implementation is the following:

import sys
from datetime import datetime

def is_narcissistic(x: int) -> bool:
    str_x = str(x)
    s = sum([int(i) ** len(str_x) for i in str_x])
    return s == x

def find_narcissistic_numbers(desired: int) -> None:
    for x in range(sys.maxsize):
        if is_narcissistic(x):
            desired -= 1
        if desired == 0:
            return

start = datetime.utcnow()
find_narcissistic_numbers(28)
print(datetime.utcnow() - start)

This code will make the number we are checking into a string and by utilizing Python iterators it will iterate over each character in the string and therefore we have step 1 down. Then in the list comprehension we also raise to the power that is the length of the string (amount of numerals) and we sum it . This is step 2 and 3. Then we check the original with that sum and get step 4.

The total run time for this code on my laptop is : 0:08:09.315972

Let us look in future parts how we can optimize this code.

#code #python