Why are strange characters output to the file?

Question

C++ / C#

In the program, I want to output the data structure to a binary file, but when I open the file, I see symbols of the form: Ёw‡ Pq‡ Фq‡ Фq‡ .
Program code:

#include <iostream>
#include <vector>
#include <stdio.h>

using namespace std;

struct t{
  string nazv;
    int semestr;
    vector <int> a;
    t()
};

t::t(){
  this->nazv = "default name";
  this->semestr = 1;
  this->a.push_back(1);
}

int main()
{
setlocale(LC_ALL, "Rus");
cout <<" введите количество предметов\n";
int n; //количество предметов
cin>>n;
  
for (int i=0;i<n;i++){
int tmp;

t name;	
cout <<"введите название предмета\n";
cin>> name.nazv;
cout << "введите количество семестров\n";
cin>> name.semestr ;//cin >> name.a ;
for (int i=0;i<name.semestr;i++){
  cout << "введите номера семестров\n";
  cin>>tmp;
  name.a.push_back(tmp);	
}
FILE * f;
f = fopen("5.txt", "wb+");
fwrite(&name, sizeof(name), 1, f);
fclose(f);
}
}

Answer 1

It is necessary to write to the file not the structures themselves, but the fields of the structure in turn. There may be another problem with the encoding.