#include <stdio.h>

#define max_students 35
#define max_name 10
#define max_number 5
#define max_results 4

struct student{
  char second_name[max_name], initials[2], number_of_book[max_number];
  int results[max_results];
  double avg_rating;
};

void sort ( struct student students[], int n, int key ){
  int i, j;
  if ( key == 1 ){
    /*for ( i = 0; i < n - 1; i++ ){
      for ( j = 0; j < n - i - 1; j++ ){
        int compare_element = 0, random_var = 1;
        while ( random_var && compare_element < max_name ){
          if ( students[j].second_name[compare_element] > students[j+1].second_name[compare_element] ){
            struct student swap = students[j];
            students[j] = students[j+1];
            students[j+1] = swap;
            random_var = 0;
          }
          else compare_element++;
          if ( compare_element == max_name + 1 ){
            compare_element = 0;
            while ( random_var && compare_element < 2 ){
              if ( students[j].initials[compare_element] > students[j+1].initials[compare_element] ){
                struct student swap = students[j];
                students[j] = students[j+1];
                students[j+1] = swap;
                random_var = 0;
              }
              else compare_element++;
            }
            break;
          }
        }
      }
    }*/
  }
  else{
    for ( i = 0; i < n - 1; i++ )
      for ( j = 0; j < n - i - 1; j++ )
        if ( students[j].avg_rating < students[j+1].avg_rating ){
          struct student swap = students[j];
          students[j] = students[j+1];
          students[j+1] = swap;
        }
  }
}

double avg_rate ( struct student student ){
  double avg = 0;
  for ( int i = 0; i < max_results; i++ )
    avg += student.results[i];
  return avg / max_results;
}

int search ( struct student students[], int n, double key ){
  int sum = 0, i, j;
  for ( i = 0; i < n; i++ ){
    int num = 0;
    for ( j = 0; j < max_results; j++ ){
      if ( students[i].results[j] < key ){
        num = 0;
        break;
      }
      else if ( students[i].results[j] == key ) num = 1;
    }
    if ( num ) sum++;
  }
  return sum;
}

void output ( struct student students[], int n, int key, int result, int type ){
  if ( key == 0 || key == 1 ){
    char types[2][15] = { "name", "average marks" };
    key == 0 ? printf ( "Information about students:\n") : NULL;
    key == 1 ? printf ( "Sorted by %s:\n", &types[type] ) : NULL;

    for ( int i = 0; i < n; i++ ){
      printf ( "[%d] %s %c.%c.\n", i+1, &students[i].second_name,
                                        students[i].initials[0],
                                        students[i].initials[1] );
      printf ( "\tRecord-book number:\t%s\n", &students[i].number_of_book );
      printf ( "\tExam results:\t\t%d, %d, %d, %d\n", students[i].results[0],
                                                      students[i].results[1],
                                                      students[i].results[2],
                                                      students[i].results[3] );
      printf ( "\n");
    }
  }
  else if ( key == 2 ){
    char types[4][35] = { "excellent students", "good students",
                       "threesome students", "students who didn't pass exams" };
    printf ( "Number of %s: %d.\n\n", &types[type], result );
  }
}

int main (){
  struct student students[max_students];
  double avg_rating = 0;
  int n, i;

  printf ( "Input number of students: " );
  scanf ( "%d", &n );

  for ( i = 0; i < n; i++ ){
    char second_name[max_name], initials[2], number_of_book[max_number];
    printf ( "Input second name and initials of %d student: ", i + 1 );
    scanf ( "%s %c.%c.", &second_name, &initials[0], &initials[1] );
    for ( int j = 0; j < max_name; j++ ){
      students[i].second_name[j] = second_name[j];
      j < 2 ? students[i].initials[j] = initials[j] : NULL;
    }

    printf ( "Input %d student record-book number: ", i + 1 );
    scanf ( "%s", &number_of_book );
    for ( int j = 0; j < max_number; j++ )
      students[i].number_of_book[j] = number_of_book[j];

    printf ( "Input %d exam results of %d student: ", max_results, i + 1 );
    scanf ( "%d %d %d %d", &students[i].results[0], &students[i].results[1],
                           &students[i].results[2], &students[i].results[3] );

    students[i].avg_rating = avg_rate ( students[i] );

    printf( "\n" );
  }

  output ( students, n, 0, 0, 0);
  printf ( "\n\n" );

  sort ( students, n, 1);
  output ( students, n, 1, 0, 0);
  printf ( "\n\n" );

  sort ( students, n, 0);
  output ( students, n, 1, 0, 1);
  printf ( "\n\n" );

  int j = 0;
  for ( i = 5; i > 1; i-- ){
    output ( students, n, 2, search ( students, n, ( double ) i ), j );
    j++;
  }

  return 1;
}