Question

我具有以下凯撒代码功能：我希望能够撤消密码并返回原始单词，我在这里为单词“ hello”工作，它将单词“ xvdei”密码化，并将其解密为“你好”。但是，它对我输入的其他任何字词均无效，我想知道如何编辑该字词，以便我输入的任何字词都可以解密为原始字词。因此，就像我输入xvdei一样，我将返回“你好”，或者如果我放入hijklm并将其移位7，我将返回“ aaaaaa”

alphabet=['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']

def decypher(text,shift):  
    # initialize ciphertext as blank string
    dtext = ""

# loop through the length of the plaintext
    for i in range(len(text)):        
    # get the ith letter from the plaintext
        l = text[i]
    # find the number position of the ith letter
        n_alphabet = alphabet.index(l)

    # find the number position of the cipher by adding the shift

        c_num = (n_alphabet + shift ) % len(alphabet) - 6 - i

    # find the cipher letter for the cipher number you computed
        c_letter = alphabet[c_num] 
    # add the cipher letter to the ciphertext
        dtext = dtext + c_letter 

# return the computed ciphertext
    return dtext

我需要解密此函数给我的原始单词：

def caesar(plaintext,shift):  
# initialize ciphertext as blank string
    ciphertext = ""

# loop through the length of the plaintext
    for i in range(len(plaintext)):        
    # get the ith letter from the plaintext
        letter = plaintext[i]
    # find the number position of the ith letter
        num_in_alphabet = alphabet.index(letter)

    # find the number position of the cipher by adding the shift 
        cipher_num = (num_in_alphabet + shift + i) % len(alphabet) 
    # find the cipher letter for the cipher number you computed
        cipher_letter = alphabet[cipher_num] 
    # add the cipher letter to the ciphertext
        ciphertext = ciphertext + cipher_letter 

# return the computed ciphertext
    return ciphertext

Answer 1

反转密码只需要继续移至达到一个完整周期的点（即其余字母）：

def decypher(text,shift): return cypher(text,len(alphabet)-shift)

也，在您的代码中：

cipher_num = (num_in_alphabet + shift + i) % len(alphabet)

应该是

cipher_num = (num_in_alphabet + shift) % len(alphabet)

如何为输入的任何单词撤消密码？

1 个答案: