Question

我遇到了一个问题并且正在努力工作我无法找到比较出错的方法。我正在尝试做多项式长除模2。

while len(binCrcGen) <= len(binPayload) and binPayload:
        if binPayload[0] == binCrcGen[0]:
                del binPayload[0]
                for j in range(len(binCrcGen)-1):
                        if binPayload[j] == binCrcGen[j+1]:
                                binPayload.insert(binPayload[j],0)
                                del binPayload[j+1]
                                print(binPayload, "binPayload")
                        else:
                                binPayload.insert(binPayload[j],1)
                                del binPayload[j+1]
                                print(binPayload, "binPayload")

然而我的输出给了我：

Input the binary data payload: 10010
Input the binary representation of the CRC generator: 11
[1, 0, 1, 0] binPayload
[1, 1, 0] binPayload
[1, 0] binPayload
[1] binPayload -- wrong here 1 xor 1 should bring 0 to list.
[1] Remainder
[1, 1] binCrCGen
The data transmitted with the payload 1001 is protected by the CRC 11 is 10011

当手动计算时，我得到剩余的00，当空白列表被删除时，它会变成空白列表。

Answer 1

您的错误出现在以下几行：

                                binPayload.insert(binPayload[j],0)
                                binPayload.insert(binPayload[j],1)

您没有在索引j处插入。您将在索引0或1处插入，具体取决于binPayload[j]。要解决此问题，请将索引更改为j而不是binPayload[j]。当你在它的时候，你可以删除你正在使用的奇怪的插入/删除东西，只需使用binPayload[j] = whatever。此外，您可以使用exclusive-or operator ^删除if / else，并且可以使用就地版本^=来保存一些重复：

binCrcGen  = [1,1]
binPayload = [1,0,0,1,0]

while len(binCrcGen) <= len(binPayload) and binPayload:
    if binPayload[0] == binCrcGen[0]:
        del binPayload[0]
        for j in range(len(binCrcGen)-1):
            binPayload[j] ^= binCrcGen[j+1]
        print(binPayload, "binPayload")
    while binPayload and binPayload[0] == 0:
        del binPayload[0]
        print(binPayload, "binPayload")

多项式长分

1 个答案: