Delphi Epta

unit Model;

interface
  uses
    SysUtils;

  type
    TStudent = record
                 Surname : String[30];
                 Firstname : String[30];
                 Patronymic : String[30];
                 Faculty : String[10];
                 Specialty : String[10];
                 Group : String[10];
                 FormOfStudy : String[10];
                 Ratings : String[30];
                 AverageScore : String[5];
               end;

    TStudentsList = record
                      Len : Word;
                      Data : array[1..1000] of TStudent;
                    end;

  function GetDataFromFile(const PathToFile: String): TStudentsList;

  procedure WriteDataToFile(var StudList: TStudentsList;
    const PathToFile: String);

  procedure AddStudent(var StudList: TStudentsList;
    const lSurname, lFirstname, lPatronymic: String;
    const lFaculty, lSpecialty, lGroup: String;
    const lFormOfStudy, lRatings: String);

  procedure DeleteStudent(var StudList: TStudentsList;
    const Index: Word);

  procedure ChangeStudent(var StudList: TStudentsList;
    const Index: Word; const lSurname, lFirstname,
    lPatronymic: String; const lFaculty, lSpecialty,
    lGroup: String; const lFormOfStudy, lRatings: String);

  function CalcAverScore(const Str: String): Real;

  function FindStudent(const StudList: TStudentsList;
    const lSurname, lFirstname, lPatronymic,
    lGroup: String): Integer;

  function GetBestStudents(const StudList: TStudentsList;
    IsPay: Boolean): TStudentsList;

  function SortRatings(const StudList: TStudentsList;
    const Pay: Boolean): TStudentsList;

  function SortSurname(const StudList: TStudentsList;
    const Group: String): TStudentsList;

implementation

  function GetDataFromFile;
  var
    DataFile : File of TStudent;
    I : Word;
  begin
    AssignFile(DataFile, PathToFile);
    Reset(DataFile);

    I := 1;
    while not Eof(DataFile) do
    begin
      Read(DataFile, Result.Data[I]);
      Inc(I);
    end;

    Result.Len := I - 1;
  end;

  procedure WriteDataToFile;
  var
    DataFile : File of TStudent;
    I : Word;
  begin
    AssignFile(DataFile, PathToFile);
    Rewrite(DataFile);

    for I := 1 to StudList.Len do
      Write(DataFile, StudList.Data[I]);
  end;

  procedure AddStudent;
  begin
    StudList.Len := StudList.Len + 1;

    with StudList.Data[StudList.Len] do
    begin
      Surname := lSurname;
      Firstname := lFirstname;
      Patronymic := lPatronymic;
      Faculty := lFaculty;
      Specialty := lSpecialty;
      Group := lGroup;
      FormOfStudy := lFormOfStudy;
      Ratings := lRatings;
      AverageScore := FloatToStr(CalcAverScore(lRatings));
    end;

  end;

  procedure DeleteStudent;
  var
    I : Word;
  begin
    if Index+1 <> StudList.Len then
      for I := Index + 1 to StudList.Len - 1 do
        StudList.Data[I] := StudList.Data[I+1];
    StudList.Data[StudList.Len].Surname := '';
    StudList.Data[StudList.Len].Firstname := '';
    StudList.Data[StudList.Len].Patronymic := '';
    StudList.Data[StudList.Len].Faculty := '';
    StudList.Data[StudList.Len].Specialty := '';
    StudList.Data[StudList.Len].Group := '';
    StudList.Data[StudList.Len].FormOfStudy := '';
    StudList.Data[StudList.Len].Ratings := '';
    StudList.Data[StudList.Len].AverageScore := '';
    Dec(StudList.Len);
  end;

  procedure ChangeStudent;
  begin
    with StudList.Data[Index+1] do
    begin
      Surname := lSurname;
      Firstname := lFirstname;
      Patronymic := lPatronymic;
      Faculty := lFaculty;
      Specialty := lSpecialty;
      Group := lGroup;
      FormOfStudy := lFormOfStudy;
      Ratings := lRatings;
      AverageScore := FloatToStr(CalcAverScore(lRatings));
    end;
  end;

  function CalcAverScore;
  var
    I, J : Byte;
  begin
    Result := 0;
    J := 0;
    I := 1;

    while I <= Length(Str) do
    begin
      if (Str[I] <> ',') and (Str[I+1] <> ',')  then
      begin
        Result := Result + StrToFloat(Str[I] + Str[I+1]);
        Inc(J);
        Inc(I);
      end
      else if (Str[I] <> ',') then
      begin
        Result := Result + StrToFloat(Str[I]);
        Inc(J);
      end;
      Inc(I);
    end;
    Result := Result / J;
  end;

  function FindStudent;
  var
    I : Word;
    IsStudFind : Boolean;
  begin
    I := 1;
    IsStudFind := False;
    Result := -1;

    while (I <= StudList.Len) and (not IsStudFind) do
    begin
      if (StudList.Data[I].Surname = lSurname)
        and (StudList.Data[I].Firstname = lFirstname)
        and (StudList.Data[I].Patronymic = lPatronymic)
        and (StudList.Data[I].Group = lGroup) then
      begin
        Result := I;
        IsStudFind := True;
      end;
      Inc(I);
    end;
  end;

  function GetBestStudents;
  var
    I : Word;
  begin
    Result.Len := 0;

    for I := 1 to StudList.Len do
    begin
      if IsPay = True then
      begin
        if (StrToFloat(StudList.Data[I].AverageScore) >= 9)
          and (StudList.Data[I].FormOfStudy = 'Платная') then
        begin
          Inc(Result.Len);
          Result.Data[Result.Len] := StudList.Data[I];
        end
      end
      else
        if (StrToFloat(StudList.Data[I].AverageScore) >= 9)
          and (StudList.Data[I].FormOfStudy = 'Бюджетная') then
        begin
          Inc(Result.Len);
          Result.Data[Result.Len] := StudList.Data[I];
        end;
    end;
  end;

  function SortRatings;
  var
    I, J : Word;
    X : Real;
    Tmp : TStudent;
  begin
    Result.Len := 0;

    if Pay = True then
    begin
      for I := 1 to StudList.Len do
      begin
        if StudList.Data[I].FormOfStudy = 'Платная' then
        begin
          Inc(Result.Len);
          Result.Data[Result.Len] := StudList.Data[I];
        end;
      end;
    end
    else
      for I := 1 to StudList.Len do
      begin
        if StudList.Data[I].FormOfStudy = 'Бюджетная' then
        begin
          Inc(Result.Len);
          Result.Data[Result.Len] := StudList.Data[I];
        end;
      end;

    for I := 2 to Result.Len do
    begin
      Tmp := Result.Data[I];
      X := StrToFloat(Result.Data[I].AverageScore);
      J := I - 1;
      while (J >= 1) and
        (StrToFloat(Result.Data[J].AverageScore) < X) do
      begin
        Result.Data[J+1] := Result.Data[J];
        Dec(J);
      end;
      Result.Data[J+1] := Tmp;
    end;
  end;

  function SortSurname;
  var
    I, J : Word;
    Tmp : TStudent;
    X : String;
  begin
    Result.Len := 0;

    for I := 1 to StudList.Len do
      if StudList.Data[I].Group = Group then
      begin
        Inc(Result.Len);
        Result.Data[Result.Len] := StudList.Data[I];
      end;

    for I := 2 to Result.Len do
    begin
      Tmp := Result.Data[I];
      X := Result.Data[I].Surname;
      J := I - 1;
      while (J >= 1) and
        (Result.Data[J].AverageScore < X) do
      begin
        Result.Data[J+1] := Result.Data[J];
        Dec(J);
      end;
      Result.Data[J+1] := Tmp;
    end;
  end;

end.