Given two char arrays, containing the alphabet, where one is the random permutation of the other, write a method that can utilize these arrays to encrypt and decrypt a given text via a simple substitution cipher.
// Switching the vectors, a and b, will decrypt an encrypted text
void Cipher(string &text, vector<char> a, vector<char> b)
{
if (text.empty() || a.size() != b.size() || a.empty())
return;
hash_map<char, char> cipher_map;
for (int i = 0; i < a.size(); i++)
cipher_map[a[i]] = b[i];
for (int i = 0; i < text.size(); i++)
{
char c = cipher_map[text[i]];
if ('\0' != c)
text[i] = c;
}
} |
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