There has got to be a better way

Ruby
1

i’m looking to simplify the below…

@tournament.rounds = Array.new(4) { Round.new }

@tournament.rounds[0].matches = Array.new(8) { Match.new }
@tournament.rounds[1].matches = Array.new(4) { Match.new }
@tournament.rounds[2].matches = Array.new(2) { Match.new }
@tournament.rounds[3].matches = Array.new(1) { Match.new }

thoughts/suggestions?

2

@tournament.rounds = Array.new(4) { Round.new }

@tournaments.rounds.inject(8) do |size, round|
round.matches = Array.new(size) { Match.new }
size / 2
end

Something like that?

3

On 7/26/06, Michael B. [email protected] wrote:

thoughts/suggestions?

–
Posted via http://www.ruby-forum.com/.

a = [8,4,2,1]
@tournament.rounds = 0.upto(3).inject([]) { |round, index|
Round.new.matches=
Array.new( a[index] ) {Match.new} }

I think that should provide the same thing that you have.

4

How about:
@t.rounds = Array.new(4) { Round.new }
@t.rounds.each_index do |i|
@t.rounds[@t.rounds.length - 1 - i] = Array.new(1 << i) {
Match.new }
end
?

5

On 25/07/06, Michael B. [email protected] wrote:

i’m looking to simplify the below…

@tournament.rounds = Array.new(4) { Round.new }

@tournament.rounds.each_with_index do |round,roundNumber|
round.matches = Array.new(2**(@tournamet.rounds.length - 1 -
roundNumber)) {Match.new}
end

6

On Wed, 26 Jul 2006, Michael B. wrote:

–
Posted via http://www.ruby-forum.com/.

this may work for your needs

 harp:~ > cat a.rb
 class Match
   def initialize(idx) @idx = idx end
   def inspect() "#{ self.class } <#{ @idx }>" end
 end

 class Round < ::Array
   def self.new(*a,&b) super(*a){|*_| Match.new *_ } end
 end

 class Tournament < ::Array
 end

 def Match(*a,&b) Match.new(*a,&b); end
 def Round(*a,&b) Round.new(*a,&b); end
 def Tournament(*a,&b) Tournament.new(*a,&b); end

 tournament = Tournament[ Round(8), Round(4), Round(2), Round(1) ]

 p tournament[0]
 p tournament[1]
 p tournament[2]
 p tournament[3]

 p tournament[0][7]
 p tournament[3][0]



 harp:~ > ruby a.rb
 [Match <0>, Match <1>, Match <2>, Match <3>, Match <4>, Match <5>,

Match <6>, Match <7>]
[Match <0>, Match <1>, Match <2>, Match <3>]
[Match <0>, Match <1>]
[Match <0>]
Match <7>
Match <0>

regards.

-a

7

A small variant on answers already posted – use reverse! to avoid
index twiddling.

Regards, Morton

--------------- start of code
! /usr/bin/ruby -w

class M
attr_accessor :ii
# **** support for pretty printing
def to_s
“M.#@ii”
end
end

class R
attr_accessor :mm, :ii
# **** support for pretty printing
def to_s
s = (mm.collect {|m| m.to_s}).join(", ")
“[R#@ii: #{s}]”
end
end

class T
def initialize
# **** start of answer
@rr = Array.new(4) {R.new}
@rr.each_with_index {|r, i| r.mm = Array.new(1 << i) {M.new}}
@rr.reverse!
# **** end of answer
# **** support for pretty printing
tag = 1
@rr.each_with_index do |r, i|
r.ii = i + 1
r.mm.each do |m|
m.ii = tag
tag += 1
end
end
end
# **** support for pretty printing
def to_s
s = (@rr.collect {|r| r.to_s}).join(", ")
“[T: #{s}]”
end
end

t = T.new
puts t => [T: [R1: M.1, M.2, M.3, M.4, M.5, M.6, M.7, M.8],
[R2: M.9, M.10, M.11, M.12], [R3: M.13, M.14],
[R4: M.15]]

--------------- end of code

8

On Jul 25, 2006, at 8:06, Michael B. wrote:

i’m looking to simplify the below…

@tournament.rounds = Array.new(4) { Round.new }

@tournament.rounds[0].matches = Array.new(8) { Match.new }
@tournament.rounds[1].matches = Array.new(4) { Match.new }
@tournament.rounds[2].matches = Array.new(2) { Match.new }
@tournament.rounds[3].matches = Array.new(1) { Match.new }

thoughts/suggestions?

I’m not a big proponent of trying to do everything in one line, because
it often results in code that’s hard to figure out when you go back to
look at it later. So I was a little surprised when this turned into one
line of active code. :slight_smile:

class Match
def initialize
# put whatever’s needed here, of course
end
end

class Tournament
attr_reader :rounds
def initialize(num_of_rounds)
@rounds = (1…num_of_rounds).collect do |round_number|
Array.new(2**(num_of_rounds-round_number)) {|i| Match.new}
end
end
end

@tournament = Tournament.new(4)

@tournament.rounds.each_with_index {|round, round_num| puts "Number of
matches in round " + (round_num + 1).to_s + " is " + round.size.to_s}

Number of matches in round 1 is 8
Number of matches in round 2 is 4
Number of matches in round 3 is 2
Number of matches in round 4 is 1