zadacha 2222

#include<iostream>
#include<fstream>
#include <string>
using namespace std;

struct student
{
    string prof;
    int group;
    int fn;
    char name[30];
    float average;
};

fstream fp;

void input(student st[])
{
    int i, n;
    do{
        cout << "\n Insert size of a students: ";
        cin >> n;
    } while (n<1 || n>30);

    fp.open("st.dat", ios::binary | ios::out);
    if (!fp){
        cout << "\n Error";
        exit(1);
    }

    for (i = 0; i<n; i++)
    {
        fflush(stdin);
        cout << "\n FN:";
        cin >> st[i].fn;
        cout << "\n Name:";
        cin >> st[i].name;
        cout << "\n Average:";
        cin >> st[i].average;
        cout << "\n Group:";
        cin>> st[i].group;
        if (st[i].group < 1 || st[i].group > 4){
            cout << "ERROR !!!"<<endl;
        }
        cin.ignore();
        cout << "\n Profesiq: ";
        getline (cin, st[i].prof);
        if (!(strcmp("E", st[i].prof.c_str()) == 0 || strcmp("AIUT", st[i].prof.c_str()) == 0)){
            cout << "ERROR !!!"<<endl;
            break;
        }
    }
    fp.write((char*)st, n*sizeof(student));
    fp.close();
}
void append()
{
    student s;
    long pos, n;
    fp.open("st.dat", ios::binary | ios::in);
    if (!fp){
        cout << "\n Error"; exit(1);
    }
    fp.seekg(0L, ios::end);
    pos = fp.tellg(); fp.close();
    fp.open("st.dat", ios::binary | ios::app);
    if (!fp){
        cout << "\n Error"; exit(1);
    }
    n = pos / (sizeof(student));
    cout << "\n Input " << n + 1 << " student \n";
    fflush(stdin);
    cout << "\n FN:"; cin >> s.fn;
    cout << "\n Name:"; cin >> s.name;
    cout << "\n Average:"; cin >> s.average;
    cout << "\n Group:"; cin >> s.group;
    cout << "\n Profesion:"; cin >> s.prof;
    fp.write((char*)&s, sizeof(student));
    fp.close();
}
void output(student st[])
{
    int i, n;
    long pos;
    student s;
    cout << "\n List of students \n ";
    fp.open("st.dat", ios::binary | ios::in);
    if (fp.fail()){ cout << "\n Error"; exit(1); }
    fp.seekg(0L, ios::end);
    pos = fp.tellg();
    fp.seekg(0L, ios::beg);
    n = pos / (sizeof(student));
    for (i = 0; i<n; i++)
    {
        fp.read((char*)&s, sizeof(student));
        st[i] = s;
    }
    fp.close();
    for (i = 0; i<n; i++)
        cout << "\n FN:" << st[i].fn << "\t Name:" << st[i].name << "\t Average:" << st[i].average << "\t Profesion: " << st[i].prof;
}
void output_excel(student st[])
{
    int i, n;
    long pos; // poziciq
    student a;
    fp.open("st.dat", ios::binary | ios::in);
    if (!fp)
    {
        cout << endl << "ERORR!!" << endl;
        exit(1);
    }
    fp.seekg(0L, ios::end); // premestva ukazatelq v kraq na faila ( L sled nulata ne 1 );
    pos = fp.tellg(); // opredelq dyljinata na faila v br baitove
    n = pos / sizeof(student); // opredelq kolko abonata ima v masiva ( delish sichki baitove na goleminata v baitove na edin abonat);
    fp.seekg(0L, ios::beg); // pozicionariash v nachaloto shtoto v momenta e v kraq i nqma da moje da prochete sudurjanieto na faila
    fp.read((char *)st, n * sizeof (student));
    fp.close();
    for ( i = 0; i < n; i++){
        if (st[i].average >= 5.5 && st[i].average <=6.0)
        {
            cout << "\n FN:" << st[i].fn << "\t Name:" << st[i].name << "\t Average:" << st[i].average << "\t Profesion: " << st[i].prof;
        }
    }
    fp.close();
}

void output_search(student st[])
{
    int i, n;
    long pos;
    student s;
    fp.open("st.dat", ios::binary | ios::in);
    if (fp.fail()){ cout << "\n Error"; exit(1); }
    fp.seekg(0L, ios::end);
    pos = fp.tellg();
    fp.seekg(0L, ios::beg);
    n = pos / (sizeof(student));
    for (i = 0; i<n; i++)
    {
        fp.read((char*)&s, sizeof(student));
        st[i] = s;
    }
    fp.close();
    int fn1;
    cout << "\n Search for student with FN : ";
    cin >> fn1;

    for (i = 0; i<n; i++)
    if (st[i].fn == fn1)
        cout << "\n FN:" << st[i].fn << "\t Name:" << st[i].name << "\t Average:" << st[i].average << "\t Profesion: " << st[i].prof;
}
void main(){
    student st[30];
    int ch;
    do{
        cout << "\n 1.Create file";
        cout << "\n 2.Append new one ";
        cout << "\n 3.List";
        cout << "\n 4.Exellent students";
        cout << "\n 5.Search on fn";
        cout << "\n 6.Exit";
        cout << "\n Your choice: ";
        cin >> ch;
        switch (ch)
        {
        case 1:input(st); break;
        case 2:append(); break;
        case 3:output(st); break;
        case 4:output_excel(st); break;
        case 5:output_search(st); break;
        }
    } while (ch != 6);
}