zSFahwc1

1function encoder
2    const_lowerBound = 'A';
3    const_upperBound = 'Z';
4    secretKey = input('Input secret key: ', 's');
5    secretKey = upper(secretKey);
6    
7    initialText = input('Input the text you desire to encrypt: ', 's');
8    initialText = upper(initialText);
9    
10    fprintf(1, 'Secret: %s\n', secretKey);
11    fprintf(1, 'Initial text: %s\n', initialText);
12    
13    keyCodes = filter(initialText, @(c) ~isspace(c));
14    
15    encrypted = '';
16    
17    for i = 1:length(keyCodes)
18        charToEncode = keyCodes(i);
19   
20        if charToEncode > const_upperBound || charToEncode < const_lowerBound
21            continue
22        end
23        
24        index = mod(i - 1, length(secretKey));
25        disp(index);
26        encodedChar = charToEncode + secretKey(index + 1);
27        
28        encodedChar = mod(encodedChar - const_lowerBound, const_upperBound - const_lowerBound + 1);
29        encodedChar = encodedChar + const_lowerBound;
30        
31        encrypted = [encrypted encodedChar];
32    end
33    
34    fprintf(1, 'Encrypted: %s\n', encrypted);
35end
36
37function filtered = filter(array, filterFunction)
38    result = [];
39    
40    for i = 1:length(array)
41        if filterFunction(array(i))
42            result = [result array(i)];
43        end
44    end
45    
46    filtered = result;
47end