vector<string> findRepeatedDnaSequences(string s) {
vector<string> result;
if(s.length() < 10) {
return result;
}
unordered_map <int, int> Map;
string substr = s.substr(0, 10);
int hash = stringHash(substr);
Map[hash]++;
for(int i = 10; i < s.length(); ++i) {
int newHash = updateHash(hash, s[i]);
Map[newHash]++;
hash = newHash;
}
for(auto it = Map.begin(); it != Map.end(); ++it) {
if(it->second > 1) {
string str = hashToStr(it->first);
result.push_back(str);
}
}
return result;
}
string FileHash::generate()
{
char buf[512];
SHA512_CTX sha;
unsigned char out[SHA512_DIGEST_LENGTH];
SHA512_Init(&sha);
while (!file_.eof()) {
memset(buf, 0x00, 512);
file_.read(buf, 512);
SHA512_Update(&sha, buf, 512);
}
SHA512_Final(out, &sha);
return hashToStr(out);
}