header.h

#pragma once

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>

#define MAX_ROWS 100
#define MAX_DATA 512
#define MARKS 3

struct student
{
    char first_name[MAX_DATA];
    char second_name[MAX_DATA];
    char patronimyc[MAX_DATA];
    int marks[MARKS];
    int set;
    int sum;
    int year;
    char letter;
};

struct clas
{
    struct student rows[MAX_ROWS];
};

struct connection
{
    FILE *file;
    struct clas *classes;
};

FILE* file_create(const char *filename, const char *mode);

struct connection* make_connection(const char *filename, const char *mode);

int int_input();

int stud_number();

struct student* set_student(struct student *st);

int set_all(struct connection *conn);

struct connection* delete_connection(struct connection *conn);

void print_student(struct student *stud);

void print_all(struct clas *cl, int students_number);

void write(struct connection *conn);

struct connection* read(struct connection *conn);

int define_student(struct student *stud);

int print_good(struct clas *classes);

int get_max_sum(struct student *rows, int students_number, int class_year);

void student_copy(struct clas *destinition, struct clas *source, int des_indx, int sour_indx);

int students_cmp(struct student *stud1, struct student *stud2);

void remove_similar(struct student *rows);

struct clas* find_best(struct clas *classes, int students_number);

void print_best(struct clas *classes);

int obtain_max_row(char *str1, char *str2);

void sort(struct clas *clas);

float get_average(struct clas *clas);

struct student* read_n(struct connection *conn);