49 lines
1.2 KiB
Python
49 lines
1.2 KiB
Python
def encode(M):
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message = format(int.from_bytes(M.encode(), "big"), "b")
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generator = "10001000000100001"
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gen_deg = len(generator)
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message += "0" * (gen_deg - 1)
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if len(message) % 2 != 0:
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message = "0" + message
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swapped = list(message)
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for i in range(gen_deg - 1):
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if swapped[i] == "0":
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swapped[i] = "1"
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else:
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swapped[i] = "0"
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message = "".join(swapped)
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while True:
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if message[0] == "0":
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message = message[1:]
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else:
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chunk = message[:gen_deg]
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if len(chunk) < gen_deg:
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chunk = "00" + chunk
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return chr(int(chunk[:8], 2)) + chr(int(chunk[8:], 2))
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remainder = format(int(chunk, 2) ^ int(generator, 2), "b")
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message = remainder + message[gen_deg:]
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def decode(N):
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message = format(int.from_bytes(N.encode(), "big"), "b")
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while len(message) % 8 != 0:
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message = "0" + message
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if __name__ == "__main__":
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M = input()
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N = encode(M)
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# print(N)
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decode(M+N)
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# 0011110110111000
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# 11000010111100101111001001111011100001010111000
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# 0011110110111000 |