为什么没有参数的构造函数似乎是此代码的问题

我无法编译此代码。似乎问题在于朋友班的构造函数，但我不明白问题在哪里。

我试图将其删除，并成功地进行了编译，但是默认的构造函数似乎也无法正常工作。

这是编译器显示的内容：

UnNamed.cpp: In constructor ‘Friends::Friends()’:
UnNamed.cpp:92:13: error: no matching function for call to ‘Friend::Friend()’
   Friends() {
             ^
UnNamed.cpp:52:3: note: candidate: Friend::Friend(std::__cxx11::string, std::__cxx11::string)
   Friend (string n, string c): Person (n, c) {
   ^~~~~~
UnNamed.cpp:52:3: note:   candidate expects 2 arguments, 0 provided
UnNamed.cpp:41:7: note: candidate: Friend::Friend(const Friend&)
 class Friend: public Person {
       ^~~~~~
UnNamed.cpp:41:7: note:   candidate expects 1 argument, 0 provided
UnNamed.cpp:41:7: note: candidate: Friend::Friend(Friend&&)
UnNamed.cpp:41:7: note:   candidate expects 1 argument, 0 provided

这是代码：

#include <iostream>
#include <string>
using namespace std;
struct Date{
  int d;
  int m;
  int y;
};

class Person{
protected:
  string name;
  string surname;
public:
  Person(){
    name = "xxx";
    surname = "xxx";
  }
  Person (string n, string c) {
    name = n;
    surname = c;
  }
  string get_surname() {
    return surname;
  }
  void print (ostream& f_out) const {
    f_out << name << " " << surname;
  }
};


class Friend: public Person {
private:
  Date bdate;
  string email;
  bool bissextile( int a ) {...}
  bool check_date() {...}
public:
  Friend (string n, string c): Person (n, c) {
    email = "xxx";
    bdate.d = 1;
    bdate.m = 1;
    bdate.y = 1;
  }
  void set_date (int d, int m, int y) {...}
  void set_email (string e) {
    email = e;
  }
  void print ( ostream& f_out) {
    f_out << name << " " << surname << " " << bdate.g << "/" << bdate.m <<"/" << " " << bdate.a << "/" << " " << email;
  }

};

class Friends {
private:
  Friend friend_list[100];
  int i;
public:
  Friends() {
    i = 0;
  } 
  void add(Friend a) {
    string err = "Out of space";
    if ( i == (100 - 1) )
      throw err;
    friend_list[i] = a;
    i++;
  }

  void print (ostream& f_out)  {
    for (int j = 0; j < i; j++)
      friend_list[j].print(f_out);
  }
};