unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils;

    const MARKS_C = 10;
    type TStudent = class
      private
        lastName : string;
        marks : array[0..MARKS_C] of byte;
        marksCount : byte;
      public
        constructor Create(newName : string);
        function getLastName : string;
        procedure setLastName(newName : string);
        function getMarksCount : byte;
        function addMark(newMark : byte) : boolean;
        function setMark(markIndex, newMark : byte) : boolean;
        function getMark(markIndex : byte) : byte;
        function averageMark : real;
        function getData : string;
    end;


implementation

    constructor TStudent.Create(newName : string);
    begin
      lastName := newName;
      marksCount := 0;
    end;

    function TStudent.getLastName():string;
    begin
      result := lastName;
    end;

    procedure TStudent.setLastName(newName : string);
    begin
      lastName := newName;
    end;

    function TStudent.getMarksCount : byte;
    begin
      result := marksCount;
    end;

    function TStudent.addMark(newMark : byte) : boolean;
    begin
      if ((newMark in [2..5]) and (marksCount < MARKS_C)) then
      begin
        marks[marksCount + 1] := newMark;
        inc(marksCount);
        result := true;
      end else
        result := false;
    end;

    function TStudent.setMark(markIndex, newMark : byte) : boolean;
    begin
      if ((newMark in [2..5]) and (markIndex in [1..MARKS_C])) then
      begin
        if (marks[markIndex] = 0) then inc(marksCount);
        marks[markIndex] := newMark;
        result := true;
      end else result := false;
    end;

    function TStudent.getMark(markIndex : byte) : byte;
    begin
      if (markIndex in [1..10]) then
        if (marks[markIndex] <> 0) then
          result := marks[markIndex];
    end;

    function TStudent.averageMark() : real;
    var
      marksSum : integer;
      i : byte;
    begin
      marksSum := 0;
      for i := 1 to marksCount do
        begin
          marksSum += marks[i];
        end;
      result := (marksSum / marksCount);
    end;

    function TStudent.getData : string;
    var
      i : byte;
      data : string;
    begin
      data := lastName;
      for i := 1 to marksCount do data += ' ' + intToStr(marks[i]);
      result := data;
    end;

    var
      student01, student02 : TStudent;
      answer, id, mark, markIndex, newMark: byte;
      lName, newName : string;

begin
  answer := 0;
  repeat
    writeln('1. Add a two students');
    writeln('2. Add marks');
    writeln('3. Change the marks');
    writeln('4. Get mark');
    writeln('5. Average number of student');
    writeln('6. All data');
    writeln('7. Exit');
    readln(answer);
    case answer of
    1:
      begin
        write('Enter the last name of the first student: ');
        readln(lName);
        student01.Create(lName);
        write('Enter the last name of the second student: ');
        readln(newName);
        student02.Create(newName);
        writeln(student01.getLastName());
      end;
    2:
      begin
        //readln;
        //write(student01.getLastName);
        //readln();
        write('1. ', student01.getLastName(), ' or 2. ', student02.getLastName(), '? 1/2: ');
        readln(id);
        write('Which mark should be added?[2..5]: ');
        readln(mark);
        case id of
        1:
          begin
            student01.addMark(mark);
          end;
        2:
          begin
            student02.addMark(mark);
          end;
        end;
      end;
    3:
      begin
        write('1. ', student01.getLastName, ' or 2. ', student02.getLastName, '? 1/2: ');
        readln(id);
        case id of
        1:
          begin
            writeln(student01.getData);
          end;
        2:
          begin
            writeln(student02.getData);
          end;
        end;
        write('Which mark should be changed by index?[1..10]: ');
        readln(markIndex);
        write('Which mark should be changed?[2..5]: ');
        readln(newMark);
        case id of
        1:
          begin
            student01.setMark(markIndex, newMark);
          end;
        2:
          begin
            student02.setMark(markIndex, newMark);
          end;
        end;
      end;
    4:
      begin
        write('1. ', student01.getLastName, ' or 2. ', student02.getLastName, '? 1/2: ');
        readln(id);
        case id of
        1:
          begin
            writeln(student01.getData);
          end;
        2:
          begin
            writeln(student02.getData);
          end;
        end;
        write('Which mark you want by index?[1..10]: ');
        readln(markIndex);
        case id of
        1:
          begin
            writeln(student01.getMark(markIndex));
          end;
        2:
          begin
            writeln(student02.getMark(markIndex));
          end;
        end;
      end;
    5:
      begin
        write('1. ', student01.getLastName, ' or 2. ', student02.getLastName, '? 1/2: ');
        readln(id);
        case id of
        1:
          begin
            writeln(student01.averageMark());
          end;
        2:
          begin
            writeln(student02.averageMark());
          end;
        end;
      end;
    6:
      begin
        writeln(student01.getData());
        writeln(student02.getData());
      end;
    end;
  until answer = 7;

  //if student01.addMark(4) then writeln('Correct.') else writeln('Error.');
  //if student02.addMark(5) then writeln('Correct.') else writeln('Error.');
  //student02.setLastName('Khafizov');
  //if student02.setMark(1, 3) then writeln('Correct.') else writeln('Error.');
  //writeln('Count of marks of student ', student01.getLastName, ' : ', student01.getMarksCount);
  //if student02.addMark(5) then writeln('Correct.') else writeln('Error.');
  //if (student02.getMark(2) <> 0) then writeln(student02.getMark(2)) else writeln('Error.');
  //writeln('Average mark of student ', student02.getLastName, ' : ', student02.averageMark : 2);
  //writeln(student01.getData);
  //writeln(student02.getData);
//
//  readln;
end.