Decode Username

decode_username.py

import math 

# note: this can easily be implemented using conditions, but I like leveraging math for it instead 

# map input to 1 (when a = x), other values (a != x) to 0; domain is ASCII table values (0-255)
# 0.0001 should be an arbitrarily small number approaching 0 to prevent dividing by zero error when x=a
def f(x, a): 
    return math.floor(1 - ( abs(x-a)/(abs(x-a) + 0.0001) ))

def decode(character):
    ascii_value = ord(character)

    return chr( ( f(ascii_value, 49) * 121 ) + ( f(ascii_value, 54) * 101 ) + ( f(ascii_value, 66) * 104 ) + ( f(ascii_value, 105) * 111 ) + ( f(ascii_value, 116) * 115 ) + ( f(ascii_value, 83) * 104 ) + ( f(ascii_value, 51) * 117 ) + ( f(ascii_value, 71) * 97 ) + ( f(ascii_value, 52) * 92 ) + ( f(ascii_value, 108) * 48 ))

def decode_string(characters):
    
    decoded_str = ""

    for character in characters:
        decoded_str += decode(character)

    return decoded_str