From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-03-26T00:31:36+09:00
Subject: Re: problem sorting

On Thu, Mar 25, 2010 at 3:58 PM, Augusto Garcia <augus1@umbc.edu> wrote:
> I am trying to sort an array using a block but somehow I am not seeing
> what I am want. First I want to sort the total, then break the tie on
> gold goldcount, silvercount and finally on bronzcount
>
> Here is my code. what am I missing? please help
>
>  # compare and order by totals
>        result = b[:total] <=> a[:total]
>        # if tied, break the number of gold medals
>        result != 0 ? result : b[:goldcount] <=> a[:goldcount]
>        result != 0 ? result : b[:silvercount] <=> a[:silvercount]
>        result != 0 ? result : b[:bronzcount] <=> a[:bronzcount]
>        result != 0 ? result : b[:country] <=> a[:country]
>  end

I assume you have an array of hashes:

irb(main):001:0> country_medals = []
=> []

irb(main):002:0> country_medals << {:country => "Spain", :total =>
100, :goldcount => 100, :silvercount => 0, :bronzecount => 0}
=> [{:country=>"Spain", :total=>100, :goldcount=>100, :silvercount=>0,
:bronzecount=>0}]

irb(main):003:0> country_medals << {:country => "US", :total => 50,
:goldcount => 50, :silvercount => 0, :bronzecount => 0}
=> [{:country=>"Spain", :total=>100, :goldcount=>100, :silvercount=>0,
:bronzecount=>0}, {:country=>"US", :total=>50, :goldcount=>50,
:silvercount=>0, :bronzecount=>0}]

irb(main):004:0> country_medals << {:country => "UK", :total => 50,
:goldcount => 45, :silvercount => 5, :bronzecount => 0}
=> [{:country=>"Spain", :total=>100, :goldcount=>100, :silvercount=>0,
:bronzecount=>0}, {:country=>"US", :total=>50, :goldcount=>50,
:silvercount=>0, :bronzecount=>0}, {:country=>"UK", :total=>50,
:goldcount=>45, :silvercount=>5, :bronzecount=>0}]

irb(main):010:0> country_medals.sort_by {|x| [-x[:total],
-x[:goldcount], -x[:silvercount], -x[:bronzecount], x[:country]]}
=> [{:country=>"Spain", :total=>100, :goldcount=>100, :silvercount=>0,
:bronzecount=>0}, {:country=>"US", :total=>50, :goldcount=>50,
:silvercount=>0, :bronzecount=>0}, {:country=>"UK", :total=>50,
:goldcount=>45, :silvercount=>5, :bronzecount=>0}]


Jesus.