Created
March 2, 2017 20:42
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Vignere Cipher
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import java.util.Scanner; | |
/* | |
* IsonProjects | |
*/ | |
public class Vignere { | |
private final String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; | |
private char matrix[][]; | |
public Vignere(){ | |
matrix = new char[26][26]; | |
int pos = 0; | |
for (int i = 0; i<alphabet.length(); i++){ | |
for (int j = 0; j < alphabet.length(); j++){ | |
int mov = (pos + j) % alphabet.length(); | |
matrix[i][j] = alphabet.charAt(mov); | |
} | |
pos++; | |
} | |
} | |
public Vignere(String alphabet){ | |
matrix = new char[alphabet.length()][alphabet.length()]; | |
int pos = 0; | |
for (int i = 0; i<alphabet.length(); i++){ | |
for (int j = 0; j < alphabet.length(); j++){ | |
int mov = (pos + j) % alphabet.length(); | |
matrix[i][j] = alphabet.charAt(mov); | |
} | |
pos++; | |
} | |
} | |
public String encode(String key, String input){ | |
String out = ""; | |
String strippedInput = input.replace(" ", ""); // remove spaces | |
key = key.toUpperCase(); | |
strippedInput = strippedInput.toUpperCase(); | |
int repeat = strippedInput.length() / key.length(); | |
String keyStr = ""; | |
for (int i = 0; i < repeat; i++){ | |
keyStr += key; | |
} | |
int surplass = strippedInput.length() % key.length(); | |
keyStr += key.substring(0, surplass); | |
int k = 0; | |
for (int i=0; i<input.length(); i++){ | |
if(input.charAt(i) == ' '){ | |
out += ' '; | |
} | |
else{ | |
int row = keyStr.charAt(k) - 'A'; | |
int col = strippedInput.charAt(k) - 'A'; | |
out += matrix[row][col]; | |
k++; | |
} | |
} | |
return out; | |
} | |
public String decode(String key, String input){ | |
String out = ""; | |
String strippedInput = input.replace(" ", ""); // remove spaces | |
key = key.toUpperCase(); | |
strippedInput = strippedInput.toUpperCase(); | |
int repeat = strippedInput.length() / key.length(); | |
String keyStr = ""; | |
for (int i = 0; i < repeat; i++){ | |
keyStr += key; | |
} | |
int surplass = strippedInput.length() % key.length(); | |
keyStr += key.substring(0, surplass); | |
int k = 0; | |
for (int i=0; i<input.length(); i++){ | |
if (input.charAt(i) == ' '){ | |
out += ' '; | |
} | |
else{ | |
int row = keyStr.charAt(k) - 'A'; | |
int col = 0; | |
for (int j=0; j<matrix[i].length; j++){ | |
if (matrix[row][j] == strippedInput.charAt(k)){ | |
col = j; | |
k++; | |
break; | |
} | |
} | |
out += (char)('A' + col); | |
} | |
} | |
return out; | |
} | |
public static void main(String[] args) { | |
Scanner scanner = new Scanner(System.in); | |
Vignere vignere = new Vignere("ABCDEFGHIJKLMNOPQRSTUVWXYZ"); | |
System.out.print("Enter key(without space): "); | |
String key = scanner.nextLine(); | |
while(true){ | |
System.out.print("Enter choice (0. Exit 1. Encode 2. Decode): "); | |
int choice = Integer.parseInt(scanner.nextLine()); | |
if (choice == 0){ | |
break; | |
}else{ | |
if (choice == 1){ | |
System.out.print("Enter string to encode: "); | |
String input = scanner.nextLine(); | |
System.out.println("Encoded output: " + vignere.encode(key, input)); | |
} | |
else{ | |
System.out.print("Enter string to encode: "); | |
String input = scanner.nextLine(); | |
System.out.println("Decoded output: " + vignere.decode(key, input)); | |
} | |
} | |
} | |
System.out.println("-----EXIT-----"); | |
} | |
} |
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