Java中的凱撒密碼（西班牙字符）

Question

我讀過this question，我想知道是否有任何方法來考慮整個字符範圍？例如，「á」，「é」，「ö」，「ñ」，而不是「」（[Space]）？ （例如，我的String是「Hello World」，標準結果是「Khoor＃Zruog」;我想刪除那個「＃」，所以結果將是「KhoorZruog」）

我確定我的回答是在這段代碼：

if (c >= 32 && c <= 127) 
     { 
      // Change base to make life easier, and use an 
      // int explicitly to avoid worrying... cast later 
      int x = c - 32; 
      x = (x + shift) % 96; 
      chars[i] = (char) (x + 32); 
     } 

但我試過一些東西，它沒有奏效。

Answer 1

作爲ASCII代碼32的空間，你不會過濾掉。您可以嘗試：

if (c >= 33 && c <= 127) 
    { 
     // Change base to make life easier, and use an 
     // int explicitly to avoid worrying... cast later 
     int x = c - 32; 
     x = (x + shift) % 96; 
     chars[i] = (char) (x + 32); 
    } 

我剛剛在if-Clause中將33改爲33，以便空格被忽略。

Answer 2

你可以使用它。它會檢查你給它的int值代表一個文字。 Character

所以你的函數看起來是這樣的：

if (Character.isLiteral(c)) 
{ 
    // Change base to make life easier, and use an 
    // int explicitly to avoid worrying... cast later 
    int x = c - Character.MIN_VALUE; 
    x = (x + shift) % Character.MAX_VALUE; 
    chars[i] = (char) (x + Character.MIN_VALUE); 
} 

Answer 3

看到這個僞 - 應該是平凡實現的：

// you need to define your own range, obviously - it's not at all obvious whether 
// e.g. "ź" should be included and that it should come after "z" 
array char_range = ['a','á','b','c','č', (...), 'z','ź','ž'] 
// the text to encode 
string plaintext = 'some text here' 
// this will contain encoded text 
stringbuilder ciphertext = '' 
// the classic Caesar Cipher shifts by 3 chars to the right 
// to decipher, reverse the sign 
int shift_by = 3 
// note: character != byte, esp. not in UTF-8 (1 char could be 1 or more bytes) 
for each character in plaintext 
    get character_position of character in char_range // e.g. "a" would return 0 
    if not in char_range // e.g. spaces and other non-letters 
     do nothing // drop character 
     // alternately, you can append it to ciphertext unmodified 
     continue with next character 
    add shift_by to character_position 
    if character_position > char_range.length 
     character_position modulo char_range.length 
    if character_position < 0 // useful for decoding 
     add char_range.length to character_position 
    get new_character at character_position 
    append new_character to ciphertext 
done