#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define NSTUDENTS 2
#define NAME_LENGTH 16
#define GROUP_LENGTH 7

struct student
{
    char name[NAME_LENGTH];
    char group[GROUP_LENGTH];
    int ses[5];
}students[NSTUDENTS],fstudents[NSTUDENTS],tmp;

int main()
{

    FILE *fp;
    int b, i, j, counter=0, f=0, n;
    char search[16];
    for (i=0; i<NSTUDENTS; i++)//
    {
        printf("enter the surname and initials <max 16 symbols>: ");
        gets(students[i].name);
        if (strlen(students[i].name)>NAME_LENGTH)
        {
            printf("Name is out of range");
            return EXIT_FAILURE;
        }
        printf("enter the group number <max 7 symbols>: ");
        scanf("%s", &students[i].group);
        getchar();
        if (strlen(students[i].group)>GROUP_LENGTH)
        {
            printf("Group name is out of range");
            return EXIT_FAILURE;
        }
        printf("enter the marks: \n");
        for (j=0; j<5; j++)
        {
            scanf("%d", &students[i].ses[j]);
        }
        getchar();
    }

    i=0;

    while (i<(NSTUDENTS-1))//
    {
        b=0;
        while (b<NSTUDENTS)
        if (students[i].name[b]>students[i+1].name[b])
        {
            tmp=students[i];
            students[i]=students[i+1];
            students[i+1]=tmp;
            b=10;
            i=0;
        }
        else
        {
            if (students[i].name[b]==students[i+1].name[b])
            {
                b++;
            }
            else
            {
                i++;
                b=10;
            }
        }
    }
    printf("\nsorted students: \n");//
    for (i=0; i<NSTUDENTS; i++)
        printf("\nstudent: %-32s group: %s", students[i].name, students[i].group);
    printf("\n");
    printf("\nstudents w/ a bad mark: \n");//
    for (i=0; i<NSTUDENTS; i++)
    {
        for (j=0; j<5; j++)
        {
            if (students[i].ses[j]==2)
            {
                printf("\nstudent: %-32s group: %s", students[i].name, students[i].group);
                counter++;
                break;
            }
        }
    }
    if (counter==0)
        printf("\nwe don't have such a students\n");

    fp=fopen("structures.txt", "wb"); //
    if (fp!=NULL)
    {
        printf("\nthe file structures.txt was created successfully for writing\n") ;
    }
    else
    {
        fprintf(stderr,"the file can't be created or open\n");
        return EXIT_FAILURE;
    }

    for (i=0; i<NSTUDENTS; i++)
    {

        fprintf(fp, "%s %s ", students[i].name, students[i].group);
        for (j=0; j<5; j++)
            fprintf(fp, "%d ", students[i].ses[j]);
        fprintf(fp, "\n");
    }
    fclose(fp);

    fp=fopen("structures.txt", "r+b"); //
    if (fp!=NULL)
    {
        printf("\nthe file structures.txt was created successfully for reading\n") ;
    }
    else
    {
        fprintf(stderr,"the file can't be created or open\n");
        return EXIT_FAILURE;
    }

    fseek(fp,0,SEEK_SET);//
	for(i=0;i<NSTUDENTS;i++)
 	{
 		fgets(fstudents[i].name, strlen(students[i].name)+1, fp);//
 		fseek(fp,1,SEEK_CUR);//
 		fgets(fstudents[i].group, strlen(students[i].group)+1, fp);//
 		fseek(fp,1,SEEK_CUR);//
 		for(j=0;j<5;j++)
 		{
 		    fscanf(fp,"%d", &fstudents[i].ses[j]);//
 		    fseek(fp,1,SEEK_CUR);
 		}
 		fseek(fp,1,SEEK_CUR);//
 	}

	   printf("\nfile test: \n");//
    for (i=0; i<NSTUDENTS; i++)
    {
        printf("\nstudent: %-16s group: %-16s", fstudents[i].name, fstudents[i].group);
        printf("marks: ");
        for (j=0;j<5;j++)
            printf("%d ",fstudents[i].ses[j]);
    }
    printf("\n");

    printf("\nSearching by Name\n");
    printf("Enter the name: ");
    fscanf(stdin, "%[^\n]", search);
    for (i=0; i<NSTUDENTS; i++)
    {
        if (strncmp(students[i].name, search, 4) == 0)
        {
            printf ("\nstudent: %s\t group: %s\t marks: ", students[i].name, students[i].group);
            for(j=0;j<5;j++)
                printf("%d ", students[i].ses[j]);
            printf("\n");
            f=1;
 		}
 	}
    if (!f)
        printf ("There is no %s\n", search);
    fclose(fp);
    return 0;
}