Векторы С++

del((char*)str[i].c_str(), static_cast<int>(strlen((char*)str[i].c_str())), (char*)result[i].c_str());

vector <string> str, result;

extern "C" void __cdecl del(char *st, int n, char *res);

extern "C" void __cdecl del(const char *st, int n, char *res);int main()
{vector <string> str, result;string s1;
    auto count = 0u;
    int j, j1, a, mas[15];cout << "How many words in your string?" << endl;
    cin >> count;
    cin.ignore();for (auto i = 0u; i < count; i++) {
        cout << "Input word number " << i + 1 << " through ENTER: ";
        getline(cin, s1);
        str.emplace_back(s1);  //str.push_back(S)
        result.emplace_back(" ");}
    cout << "\nYour words:\n";
    for (const auto &i : str) cout << i << '\n';
    cout << "How many words you want to edit?" << endl;
    cin >> a;
    cout << "Input numbers of words you want to edit through ENTER" << endl;
    for (int i = 0; i < a; i++) {
        cin >> mas[i];
    }
 
    cout << "Changed words:" << endl;
    for (int i = 0; i < count; i++) {
        for (j = 0; j < a; j++) {
            if (i == mas[j]-1 )
            {size_t len = str[i].length();
                result[i].resize(len);
                del(str[i].c_str(), len, &result[i][0]);
                cout <<result[i] << endl;
            }
        }
    }
}