text: class Solution {
  public:
      vector<string> findRepeatedDnaSequences(string s) {
          map<string, int> cnt;
          for(int i = 0; i + 9 < s.length(); ++i){
              cnt[s.substr(i, 10)] += 1;
          }
          
          vector<string> answer;
          for(const pair<string, int>& P: cnt){
              if(P.second > 1){
                  answer.push_back(P.first);
              }
          }
          
          return answer;
      }
  };