[Snippet] Students

[thoga31]

Só porque sim, aqui vai a resolução de um exercício muito simples: ler 20 notas de alunos, registar num ficheiro, e depois calcular as positivas, negativas e média.

E só porque sim, na altura deu-me na cabeça fazer um código mais "ofuscado" 😄

O que acham?

{$mode objfpc}
program students;
uses sysutils, strutils;

const DIM = 20;
     FNAME = 'teste';
     TAB = '    ';

type TArrayInt = array of smallint;
    TFileInt = file of smallint;

var grades, negative_grades : TArrayInt;
   n : smallint;
   GradeFile : TFileInt;

procedure FillArray(var arr : TArrayInt; dimension : longint; const prompt : string);
begin
   setlength(arr, dimension-1);
   for dimension := low(arr) to high(arr) do begin
       write(AnsiReplaceText(prompt, '@{COUNT}', IntToStr(dimension)));
       readln(arr[dimension]);
   end;
end;

procedure CopyArrayToFile(const arr : TArrayInt; out f : TFileInt);
var elem : smallint;
begin
   for elem in arr do
       write(f, elem);
end;

procedure GetArrayFromFile(var f : TFileInt; out arr : TArrayInt);
var i : smallint = 0;
begin
   seek(f,0);
   SetLength(arr, FileSize(f));
   while not eof(f) do begin
       read(f, arr[i]);
       inc(i);
   end;
end;

function CountPositive(arr : TArrayInt; const minimum : smallint = 0) : smallint;
var elem : smallint;
begin
   CountPositive := 0;
   for elem in arr do
       if elem >= minimum then
           inc(CountPositive);
end;

function CountPositive(var f : TFileInt; const minimum : smallint = 0) : smallint; overload;
var arr : TArrayInt;
begin
   GetArrayFromFile(f, arr);
   CountPositive := CountPositive(arr, minimum);
end;

procedure GetNegative(arr : TArrayInt; out neg : TArrayInt; const minimum : smallint = 0);
var elem : smallint;
begin
   for elem in arr do
       if elem < minimum then begin
           SetLength(neg, length(neg)+1);
           neg[length(neg)-1] := elem;
       end;
end;

procedure GetNegative(var f : TFileInt; out neg : TArrayInt; const minimum : smallint = 0); overload;
var arr : TArrayInt;
begin
   GetArrayFromFile(f, arr);
   GetNegative(arr, neg, minimum);
end;

function Average(arr : TArrayInt) : real;
var elem : smallint;
begin
   Average := 0.0;
   for elem in arr do
       Average := Average + elem;
   Average := Average / length(arr);
end;

function Average(var f : TFileInt) : real; overload;
var arr : TArrayInt;
begin
   GetArrayFromFile(f, arr);
   Average := Average(arr);
end;

begin
   assign(GradeFile, FNAME);
   FillArray(grades, 5, 'Write the @{COUNT} grade: ');
   rewrite(GradeFile);
   CopyArrayToFile(grades, GradeFile);
   close(GradeFile);
   reset(GradeFile);
   writeln('There is/are ', CountPositive(GradeFile), ' positive grades.');
   GetNegative(GradeFile, negative_grades, 10);
   writeln('Negative grades:');
   for n in negative_grades do
       writeln(TAB, n);
   writeln('Average = ', Average(GradeFile));
   close(GradeFile);
   readln;
end.