Huawei Hackthon Nnajing 2015 Solution

hackathon.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

__author__ = 'Eric Fu'

cipher_file = open('cipher.txt', 'r')
dict_file = open('dictionary.tsv', 'r')

matrix = []
for line in dict_file.readlines():
    words = line.strip().split('\t')
    matrix.append(words)

plain = ''

prev_x, prev_y = 0, 0
for cipher in cipher_file.readlines():
    cipher = int(cipher)
    x = ((cipher >> 18) & 0x7f)
    prev_x, x = x, x ^ prev_x
    y = ((cipher >> 2) & 0x7f)
    prev_y, y = y, y ^ prev_y
    plain = plain + matrix[x - 1][y - 1]

cipher_file.close()
dict_file.close()

print(plain)