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struct LonelyPeople{
    char name[30];
    char sex[10] ;
    int age;
    char education[50];
    int height ;
}
 
extern vector <LonelyPeople> ManyPeople;

vector <LonelyPeople> ManyPeople;
 
void __fastcall TForm1::N2Click(TObject *Sender)
{
    SaveDialog1->Execute();
    FILE *f = fopen(AnsiString(SaveDialog1->FileName).c_str(), "w+b");
 
    if( f )
    {
        for (int i = 0; i < ManyPeople.size(); i++) {
            fwrite(&ManyPeople[i], sizeof(LonelyPeople), sizeof(ManyPeople), f);
        }
 
    }
    else
    {
        ShowMessage("file error");
    }
 
    fclose( f );
}
 
void __fastcall TForm1::N3Click(TObject *Sender)
{
    ManyPeople.clear(); // очистить массив при загрузке
 
    OpenDialog1->Execute();
    FILE *f = fopen(AnsiString(OpenDialog1->FileName).c_str(), "r+b");
 
    if( f==0 )
    {
        ShowMessage("file error");return;
    }
 
    for(int i=0;i<ManyPeople.max_size();i++)
    {
        LonelyPeople s;
        fread(&s,sizeof(LonelyPeople),1,f);
        if(feof(f)) break;
        ManyPeople.push_back(s);
    }
 
    fclose(f);
}

for(auto p:ManyPeople)
  fwrite(&p,sizeof(p),1,f);

for(auto p=ManyPeople.begin();p!=ManyPeople.end();++p)
  fwrite(p,sizeof(*p),1,f);

for (int i = 0; i < ManyPeople.size(); i++)

for(int i=0;i<ManyPeople.max_size();i++)

fwrite(&ManyPeople[i], sizeof(char), sizeof(LonelyPeople), f);

    unsigned int size = ManyPeople.size();
    fwrite(&size, sizeof(char), sizeof(size), f);
    for (size_t i = 0; i < size; i++) {
        fwrite(&ManyPeople[i], sizeof(char), sizeof(LonelyPeople), f);
    }

    unsigned int size = 0;
    fread(&size, sizeof(char), sizeof(size), f);
    for(size_t i = 0; i < size; i++)
    {
        if(feof(f)) break;
 
        LonelyPeople s;
        fread(&s, sizeof(char), sizeof(s), f);
        ManyPeople.push_back(s);
    }

    
while(!feof(f))
    {
        LonelyPeople s;
        fread(&s,sizeof(LonelyPeople),1,f);
        ManyPeople.push_back(s);
    }

fwrite(&ManyPeople[i], sizeof(char), sizeof(LonelyPeople), f);