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4 | 4 | * A Java implementation of Vigenere Cipher. |
5 | 5 | * |
6 | 6 | * @author straiffix |
| 7 | + * @author beingmartinbmc |
7 | 8 | */ |
8 | 9 | public class Vigenere { |
9 | 10 |
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10 | 11 | public static String encrypt(final String message, final String key) { |
11 | 12 |
|
12 | | - String result = ""; |
| 13 | + StringBuilder result = new StringBuilder(); |
13 | 14 |
|
14 | 15 | for (int i = 0, j = 0; i < message.length(); i++) { |
15 | 16 | char c = message.charAt(i); |
16 | 17 | if (Character.isLetter(c)) { |
17 | 18 | if (Character.isUpperCase(c)) { |
18 | | - result += (char) ((c + key.toUpperCase().charAt(j) - 2 * 'A') % 26 + 'A'); |
| 19 | + result.append((char) ((c + key.toUpperCase().charAt(j) - 2 * 'A') % 26 + 'A')); |
19 | 20 |
|
20 | 21 | } else { |
21 | | - result += (char) ((c + key.toLowerCase().charAt(j) - 2 * 'a') % 26 + 'a'); |
| 22 | + result.append((char) ((c + key.toLowerCase().charAt(j) - 2 * 'a') % 26 + 'a')); |
22 | 23 | } |
23 | 24 | } else { |
24 | | - result += c; |
| 25 | + result.append(c); |
25 | 26 | } |
26 | 27 | j = ++j % key.length(); |
27 | 28 | } |
28 | | - return result; |
| 29 | + return result.toString(); |
29 | 30 | } |
30 | 31 |
|
31 | 32 | public static String decrypt(final String message, final String key) { |
32 | | - String result = ""; |
| 33 | + StringBuilder result = new StringBuilder(); |
33 | 34 |
|
34 | 35 | for (int i = 0, j = 0; i < message.length(); i++) { |
35 | 36 |
|
36 | 37 | char c = message.charAt(i); |
37 | 38 | if (Character.isLetter(c)) { |
38 | 39 | if (Character.isUpperCase(c)) { |
39 | | - result += ((char) ('Z' - (25 - (c - key.toUpperCase().charAt(j))) % 26)); |
| 40 | + result.append((char) ('Z' - (25 - (c - key.toUpperCase().charAt(j))) % 26)); |
40 | 41 |
|
41 | 42 | } else { |
42 | | - result += ((char) ('z' - (25 - (c - key.toLowerCase().charAt(j))) % 26)); |
| 43 | + result.append((char) ('z' - (25 - (c - key.toLowerCase().charAt(j))) % 26)); |
43 | 44 | } |
44 | 45 | } else { |
45 | | - result += c; |
| 46 | + result.append(c); |
46 | 47 | } |
47 | 48 |
|
48 | 49 | j = ++j % key.length(); |
49 | 50 | } |
50 | | - return result; |
| 51 | + return result.toString(); |
51 | 52 | } |
52 | 53 |
|
53 | 54 | public static void main(String[] args) { |
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