Имена_и_фамилии_2.2

#include <bits/stdc++.h>
using namespace std;

class Person {
private:
    map<int, string> fn;
    map<int, string> sn;


    string FirstName(const int &year) {
        string first_name = " with unknown first name";
        for (const pair<int, string> &p : fn) {
            if (p.first <= year)
                first_name = p.second;
            else
                break;
        }
        return first_name;
    }


    string LastName(const int &year) {
            string last_name = "with unknown last name";
            for (const pair<int, string> &p : sn) {
                if (p.first <= year)
                    last_name = p.second;
                else
                    break;
            }
            return last_name;
        }


    bool FirstNameHistoryExists(const int &year){
    int cnt = 0;
    for (const auto &p : fn) {
        if (p.first > year) break;
        else cnt++;
    }
    if (cnt >= 2) return true;
    else return false;
}


    bool LastNameHistoryExists(const int &year) {
        int cnt = 0;
        for (const auto &p : sn) {
            if (p.first > year)
                break;
            else
                cnt++;
        }
        if (cnt >= 2)
            return true;
        else
            return false;
    }


    void FillFirstNames(vector<string> &v, const int &year) {
        for (const pair<int, string> &p : fn) {
                if (p.first <= year)
                    v.push_back(p.second);
                else
                    break;
            }
            reverse(begin(v), end(v));
            v.erase(unique(begin(v), end(v)), end(v));
    }


    void FillLastNames(vector<string> &v, const int &year) {
    for (const pair<int, string> &p : sn) {
                if (p.first <= year)
                    v.push_back(p.second);
                else
                    break;
            }
            reverse(begin(v), end(v));
            v.erase(unique(begin(v), end(v)), end(v));
}
public:


    void ChangeFirstName(const int &year, const string &first_name) {
        fn[year] = first_name;
    }


    void ChangeLastName(const int &year, const string &last_name) {
        sn[year] = last_name;
    }


    string GetFullName(const int &year) {
        if (FirstName(year) == " with unknown first name" && LastName(year) == "with unknown last name")
            return "Incognito";
        if (FirstName(year) == " with unknown first name")
            return LastName(year) + FirstName(year);
        return FirstName(year) + ' ' + LastName(year);
    }


    string GetFullNameWithHistory(const int &year) {
        string s = GetFullName(year);
        if (s == "Incognito")
            return "Incognito";
        if (FirstName(year) == " with unknown first name") {
            if (!LastNameHistoryExists(year))
                return LastName(year) + " with unknown first name";
            vector<string> v;
            FillLastNames(v, year);
            s = v[0] + " (" + v[1];
            for (int i = 2; i < v.size(); i++) {
                s += ", " + v[i];
            }
            s += ") with unknown first name";
            return s;
        }
        if (LastName(year) == "with unknown last name") {
            if (!FirstNameHistoryExists(year))
                return FirstName(year) + " with unknown last name";
            vector<string> v;
            FillFirstNames(v, year);
            s = v[0] + " (" + v[1];
            for (int i = 2; i < v.size(); i++) {
                s += ", " + v[i];
            }
            s += ") with unknown last name";
            return s;
        }
        vector<string> v;
        if (FirstNameHistoryExists(year)) {
            FillFirstNames(v, year);
            s = v[0] + " (" + v[1];
            for (int i = 2; i < v.size(); i++) {
                s += ", " + v[i];
            }
            s += ") ";
        } else
            s = FirstName(year) + ' ';
        v.clear();
        if (LastNameHistoryExists(year)) {
            FillLastNames(v, year);
            s += v[0] + " (" + v[1];
            for (int i = 2; i < v.size(); i++) {
                s += ", " + v[i];
            }
            s += ")";
        } else
            s += LastName(year);
        return s;
    }
};

int main() {
  Person person;

  person.ChangeFirstName(1965, "Polina");
  person.ChangeLastName(1967, "Sergeeva");
  for (int year : {1900, 1965, 1990}) {
    cout << person.GetFullNameWithHistory(year) << endl;
  }

  person.ChangeFirstName(1970, "Appolinaria");
  for (int year : {1969, 1970}) {
    cout << person.GetFullNameWithHistory(year) << endl;
  }

  person.ChangeLastName(1968, "Volkova");
  for (int year : {1969, 1970}) {
    cout << person.GetFullNameWithHistory(year) << endl;
  }

  person.ChangeFirstName(1990, "Polina");
  person.ChangeLastName(1990, "Volkova-Sergeeva");
  cout << person.GetFullNameWithHistory(1990) << endl;

  person.ChangeFirstName(1966, "Pauline");
  cout << person.GetFullNameWithHistory(1966) << endl;

  person.ChangeLastName(1960, "Sergeeva");
  for (int year : {1960, 1967}) {
    cout << person.GetFullNameWithHistory(year) << endl;
  }

  person.ChangeLastName(1961, "Ivanova");
  cout << person.GetFullNameWithHistory(1967) << endl;

  return 0;
}