From: Robert Klemme <shortcutter@...>
Date: 2009-12-03T17:16:23+09:00
Subject: Re: Help with complex array transformation

2009/12/3 Bruno Moura <brunormoura@gmail.com>:
> I have a following method
>
> view(all_people, begin_date, end_date)
>
> That's give me an array like this:
>
> # for a first day (day 1)
> view("*", '2009-12-01 00:00:00', '2009-12-01 24:59:59')

I would rather change timestamp strings into objects of class Time or
DateTime because that is what they are You can do proper comparison
etc.  I am aware that you can also do that with your string format but
if it is a timestamp it's usually better to treat it as such.

> [[name_person1, room1], [name_person2, room2], [name_person3, room2]]
>
> # for a second day (day 2)
> view("*", '2009-12-02 00:00:00', '2009-12-02 24:59:59')
>
> [[name_person1, room1], [name_person3, room1], [name_person2, room2]]
>
>
> And I need to organize theses arrays in a following structure:
>
> [{room1 => [{day1 => [name_person1]},
>            {day2 => [name_person1, name_person3]}]
>  },
>  {room2 => [{day1 => [name_person2, name_person3]},
>            {day2 => [name_person2]}]
>  }]

Why so many nesting levels?  Why not

{room1 => [{day1 => [name_person1]},
           {day2 => [name_person1, name_person3]}]
 },
 {room2 => [{day1 => [name_person2, name_person3]},
           {day2 => [name_person2]}]
 }

Or even

{room1 => {day1 => [name_person1]},
           {day2 => [name_person1, name_person3]}
 },
 {room2 => {day1 => [name_person2, name_person3]},
           {day2 => [name_person2]}
 }

Methinks you are making the structure much more complex than
necessary, especially in light of the desired output:

> And finally put this array in a cvs strings
>
> room1; day1; name_person1
> room1; day2; name_person1
> room1; day2; name_person3
>
> room2; day1; name_person2
> room2; day1; name_person3
> room2; day2; name_person2
>
> I tried some scripts for hours but I didn't do this job!
> Too complicated for my.

See Bertram's solution.  I would have done it a bit different, mainly
including sorting.

room_day_assignments = Hash.new {|h,k| h[k] = Hash.new {|a,b| a[b] = []} }

days.each do |day|
  v = view...
  v.each do |person, room|
    room_day_assignments[room][day] << person
  end
end

# output
room_day_assignments.keys.sort.each do |room|
  room_day = room_day_assignments[room]
  room_day.keys.sort.each do |day|
    room_day[day].each do |person|
      printf "%s;%s;%s\n", room, day, person
    end
  end
end

Untested.

Cheers

robert

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