SRM 519 Div2 Easy WhichDay

1週間の内会議が行われる曜日を知りたい.
6人の同僚は会議が行われない曜日を知ってる.
それ以外の曜日が答え.

class WhichDay
{
public:
  string getDay(vector <string> notOnThisDay)
    {
      vector<string> week(7);
      week[0] = "Saturday";
      week[1] = "Sunday";
      week[2] = "Monday";
      week[3] = "Tuesday";
      week[4] = "Wednesday";
      week[5] = "Thursday";
      week[6] = "Friday";
      for(int i = 0; i < 7; i++){
        bool notfound = true;
        for(int j = 0; j < notOnThisDay.size(); j++){
          if (week[i] == notOnThisDay[j]) notfound = false;
        }
        if(notfound) return week[i];
      }
    }
};