#include <iostream>
#include <string.h>
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <fstream>
using namespace std;
struct birthday
{
	int day;
	int month;
	int year;
};
struct STUDENTS
{
	char surname[20];
	char name[20];
	char familiya[20];
	birthday born;
	int mark;
	int num;
};

void sort(STUDENTS* student, int fcount)
{
	for (int i = 0; i < fcount - 1; i++)
		for (int j = i + 1; j < fcount; j++)
			if (strcmp(student[i].surname, student[j].surname) > 0)
			{
				STUDENTS t = student[i];
				student[i] = student[j];
				student[j] = t;
			}
}
int main()
{
	FILE* fstud;
	fstud = fopen("D://students.bin", "ab");

	fclose(fstud);
	int N;
	int count = 0;
	cout << "How many students in the group?\n";
	cin >> N;
	STUDENTS* student = new STUDENTS[N];
	STUDENTS* fmass = new STUDENTS[N];
	int fcount = 0;
	int q;
	int low_count = 0;
	int mid_count = 0;
	int high_count = 0;
question:
	    cout << "\nВыберите пункт меню: "<< endl;
		cout << "1.Добавить студента. " << endl;
		cout << "2.Показать всех студентов. " << endl;
		cout << "3.Поиск студента по: " << endl;
	    cout << "4.Удалить студента по номеру " << endl;
	    cout << "5.По оценкам " << endl;
	cin >> q;
	switch (q)
	{
	case 1:
		if (count == N)
			N++;
		cout << "Enter name: ";
		cin >> student[count].name;
		cout << "Enter surname: ";
		cin >> student[count].surname;
		cout << "Enter patronymic: ";
		cin >> student[count].familiya;
		cout << "Enter date of birth(day/space/month/space/year): ";
		cin >> student[count].born.day;
		cin >> student[count].born.month;
		cin >> student[count].born.year;
		cout << "Enter avarage mark from 0 to 100: ";
		cin >> student[count].mark;
		student[count].num = count + 1;
		fopen("students.bin", "ab");
		fwrite(&student[count], sizeof(STUDENTS), 1, fstud);
		fclose(fstud);
		count++;

		goto question;
	case 2:
		fopen("students.bin", "rb");
		for (int i = 0; i < count; i++)
			fread(&fmass[i], sizeof(STUDENTS), 1, fstud);
		sort(fmass, count);
		for (int i = 0; i < count; i++)
		{
			student[i].num = i + 1;
			fmass[i].num = i + 1;
			cout << fmass[i].num << " " << fmass[i].surname << " " << fmass[i].name << " " << fmass[i].familiya << " " << fmass[i].born.day << "." << fmass[i].born.month << "." << fmass[i].born.year << " " << fmass[i].mark;
			cout << "\n";
		}
		fclose(fstud);
		goto question;
	case 3:
		sort(fmass, count);
		fopen("students.bin", "rb");
		cout << "1.By surname\n";
		cout << "2.By marks\n";
		cout << "3.By date of birth\n";
		cin >> q;
		switch (q)
		{
		case 1:
			cout << "Enter surname: ";
			char sur[20];
			cin >> sur;
			for (int i = 0; i < count; i++)
			{
				fread(&fmass[i], sizeof(STUDENTS), 1, fstud);
				if (!strcmp(sur, fmass[i].surname))
				{
					cout << fmass[i].num << " " << fmass[i].surname << " " << fmass[i].name << " " << fmass[i].familiya << " " << fmass[i].born.day << "." << fmass[i].born.month << "." << fmass[i].born.year << " " << fmass[i].mark;
					cout << "\n";
				}
			}
			fclose(fstud);
			goto question;
		case 2:
			cout << "From mark: ";
			int fmark;
			cin >> fmark;
			cout << "To mark: ";
			int tmark;
			cin >> tmark;
			for (int i = 0; i < N; i++)
			{
				if (fmass[i].mark >= fmark && fmass[i].mark <= tmark)
				{
					cout << fmass[i].num << " " << fmass[i].surname << " " << fmass[i].name << " " << fmass[i].familiya << " " << fmass[i].born.day << "." << fmass[i].born.month << "." << fmass[i].born.year << " " << fmass[i].mark;
					cout << "\n";
				}
			}
			fclose(fstud);
			goto question;
		case 3:
			cout << "Enter date of birth(day/space/month)";
			int day1;
			int month1;
			cin >> day1;
			cin >> month1;
			for (int i = 0; i < count; i++)
			{
				fread(&fmass[i], sizeof(STUDENTS), 1, fstud);
				if (fmass[i].born.day == day1 && fmass[i].born.month == month1)
				{
					cout << fmass[i].num << " " << fmass[i].surname << " " << fmass[i].name << " " << fmass[i].familiya << " " << fmass[i].born.day << "." << fmass[i].born.month << "." << fmass[i].born.year << " " << fmass[i].mark;
					cout << "\n";
				}
			}
			fclose(fstud);
			goto question;

		}
	case 4:
		cout << "Enter student's number:";
		int num1;
		cin >> num1;
		fopen("students.bin", "wb");
		for (int i = num1 - 1; i < count - 1; i++)
		{
			strcpy(student[i].name, student[i + 1].name);
			strcpy(student[i].surname, student[i + 1].surname);
			strcpy(student[i].familiya, student[i + 1].familiya);
			student[i].born.day = student[i + 1].born.day;
			student[i].born.month = student[i + 1].born.month;
			student[i].born.year = student[i + 1].born.year;
			student[i].mark = student[i + 1].mark;
			student[i].num = student[i + 1].num;
		}
		for (int i = 0; i < count - 1; i++)
			fwrite(&student[i], sizeof(STUDENTS), 1, fstud);
		fclose(fstud);
		count--;
		goto question;
	case 5:
		low_count = 0;
		mid_count = 0;
		high_count = 0;
		fopen("low_mark.bin", "wb");
		fclose(fstud);
		fopen("mid_mark.bin", "wb");
		fclose(fstud);
		fopen("high_mark.bin", "wb");
		fclose(fstud);
		sort(student, count);
		for (int i = fcount; i < count; i++)
		{
			if (student[i].mark < 50)
			{
				low_count++;
				fopen("low_mark.bin", "ab");
				fwrite(&student[i], sizeof(STUDENTS), 1, fstud);
				fclose(fstud);
			}
			else
				if (student[i].mark < 70)
				{
					mid_count++;
					fopen("mid_mark.bin", "ab");
					fwrite(&student[i], sizeof(STUDENTS), 1, fstud);
					fclose(fstud);
				}
				else
					if (student[i].mark < 101)
					{
						high_count++;
						fopen("high_mark.bin", "ab");
						fwrite(&student[i], sizeof(STUDENTS), 1, fstud);
						fclose(fstud);
					}
		}
		STUDENTS low[5];
		STUDENTS mid[5];
		STUDENTS high[5];
		cout << "1.High mark students \n";
		cout << "2.Middle mark students\n";
		cout << "3.Low mark students\n";
		cin >> q;
		switch (q)
		{
		case 1:
			fopen("high_mark.bin", "rb");
			for (int i = 0; i < high_count; i++)
				fread(&high[i], sizeof(STUDENTS), 1, fstud);
			for (int i = 0; i < high_count; i++)
			{
				cout << high[i].num << " " << high[i].surname << " " << high[i].name << " " << high[i].familiya << " " << high[i].born.day << "." << high[i].born.month << "." << high[i].born.year << " " << high[i].mark;
				cout << "\n";
			}
			fclose(fstud);
			goto question;
		case 2:
			fopen("mid_mark.bin", "rb");
			for (int i = 0; i < mid_count; i++)
				fread(&mid[i], sizeof(STUDENTS), 1, fstud);
			for (int i = 0; i < mid_count; i++)
			{
				cout << mid[i].num << " " << mid[i].surname << " " << mid[i].name << " " << mid[i].familiya << " " << mid[i].born.day << "." << mid[i].born.month << "." << mid[i].born.year << " " << mid[i].mark;
				cout << "\n";
			}
			fclose(fstud);
			goto question;
		case 3:
			fopen("low_mark.bin", "rb");
			for (int i = 0; i < low_count; i++)
				fread(&low[i], sizeof(STUDENTS), 1, fstud);
			for (int i = 0; i < low_count; i++)
			{
				cout << low[i].num << " " << low[i].surname << " " << low[i].name << " " << low[i].familiya << " " << low[i].born.day << "." << low[i].born.month << "." << low[i].born.year << " " << low[i].mark;
				cout << "\n";
			}
			fclose(fstud);
			goto question;

		}
		goto question;


	}
	return 0;
}