--  Solution to Advent of Code 2020, Day 6
------------------------------------------
--  Custom Customs
--
--  https://adventofcode.com/2020/day/6
--
--  Full Ada version.
--
with Ada.Strings.Fixed, Ada.Text_IO;

procedure AoC_2020_06_Full_Ada is
  total : Integer;
  new_group : Boolean;
  subtype Answer_Range is Character range 'a' .. 'z';
  type Yes_Answer is array (Answer_Range) of Boolean;
  r, rg : Yes_Answer;
  --
  procedure Collect_Group_Total is
    g : Natural := 0;
  begin
    for c in Answer_Range loop if rg (c) then g := g + 1; end if; end loop;
    total := total + g;
    new_group := True;
  end Collect_Group_Total;
  --
  use Ada.Strings.Fixed, Ada.Text_IO;
  f : File_Type;
begin
  for part in 1 .. 2 loop
    Open (f, In_File, "aoc_2020_06.txt");
    total := 0;
    new_group := True;
    while not End_Of_File (f) loop
      declare
        s : constant String := Get_Line (f);
      begin
        if s = "" then
          Collect_Group_Total;
        else
          for c in Answer_Range loop
            r (c) := Index (s, (1 => c)) > 0;
          end loop;
          if new_group then
            rg := r;
            new_group := False;
          elsif part = 1 then
            rg := rg or r;
          else
            rg := rg and r;
          end if;
        end if;
      end;
    end loop;
    Collect_Group_Total;
    Put_Line ("Part" & Integer'Image (part) & ' ' & Integer'Image (total));
    Close (f);
  end loop;
end AoC_2020_06_Full_Ada;