[BaekJoon] - 10936 base64 디코딩

 

10936번: BASE64 디코딩

#!/bin/python3
# base64 디코딩

import string

BIT = 8

if __name__ == "__main__":
    table = string.ascii_uppercase + string.ascii_lowercase + string.digits + "+/"
    b64_table = dict()
    count = 0
    
    # Create base64 Table
    for char in table:
        b64_table[char] = str(count)
        count += 1
    
    # Input cipher text
    cipher = input("").replace("=","")
    reverse = ''
    
    # cipher => ascii
    for char in cipher:
        reverse += b64_table[char]+" "
        
    # ascii => binary
    reverse = reverse.strip().split(" ")
    binary = ''
    for i in reverse:
        binary += bin(int(i))[2:].zfill(6)

    count = int(len(binary) / BIT)
    plaintext = ''
    for i in range(0,count):
        plaintext += chr(int(binary[i * BIT : (i+1) * BIT], 2))
    print(plaintext)