Factorial (n!) resolvido

Program ExercFactorial;
uses Crt;

var N, i : integer;
    Fact : real; { para ultrapassar o limite dos inteiros }

Begin
   clrscr;
   Fact := 1;

   write('Cálculo de N! - Introduza um número inteiro: ');
   readln(N);
   if N in [0, 1] then
      writeln(N, '! = ', 1)
   else
      begin
         for i := 2 to N do Fact := Fact * i;
         writeln(N, '! = ', Fact:1:0);
      end;

   readkey;
End.

Real Programmers don't need comments-- the code is obvious.