sevenmaxis

customer = {  <id> => { :sex => <sex>, :height => <height>, :age => <age>, :sum => <sum>, :index => <index> } }
class Storage
  def initialize
    h = Hash.new{|hash,key| hash[key]=[]}
    @storage = { :sex => h.dup, :height => h.dup, :age => h.dup, :sum => h.dup, :index => h.dup }
  end
  def add_customer( expr)
    # it should return id of customer
  end
  def find( search_expr)

sevenmaxis

class Array

  def get_max(index,start)
    index = 2*index + 1 - start
    self[index] > self[index+1] ? index : index+1
  end

  def heapsort
    0.upto(length-3) do |start|

sevenmaxis

def bench(repetitions=100, &block)
  require 'benchmark'
  Benchmark.bmbm do |b|
    b.report{ repetitions.times &block }
  end
  nil
end

sevenmaxis

class Trie
  def initilize
    @trie = Hash.new
  end
  def build(str)
    node = @trie
    str.each_char do |ch|
      prev_node = node
      node = prev_node[ch] = Hash.new unless node[ch]
    end

sevenmaxis

ruby -rwebrick -e 'WEBrick::HTTPServer.new(:Port=>8000,:DocumentRoot=>".").start'

sevenmaxis

a = [{:amount => "500.0", :when => "2012-03-13"},
     {:amount => "500.0", :when => "2012-03-24"},
     {:amount => "100.0", :when => "2012-04-14"},
     {:amount => "100.0", :when => "2012-04-16"}]

compressed = a.group_by{|hash| hash[:when][0,7]}
 .map{|k,v| {:when=>k,:amount=>v.reduce{|sum,hash| sum+hash[:amount].to_i}}}

[ {:when => "2012-03", :amount => 1000},
  {:when => "2012-04", :amount => 200}]

sevenmaxis

#user.rb
class User < SmartDB  
  rename_table_to :Customer
  attr_accessor :address, :rename_to => :location
end

#After running rake smart task, the table, class, file and attribute will be modified to this

#customer.rb
class Customer < SmartDB

sevenmaxis

class Array
  def partition3
    Array.new(3){|_| []}.tap{|a| each{|x| a[yield(x)] << x }}
  end
  def qsort
    return self.dup if size < 2
    central, left, right = partition3{|x| first <=> x}
    left.qsort + central + right.qsort
  end
end

sevenmaxis

a = [
  {"player_id":1 , "matches":2, "goals": 5}, 
  {"player_id":2 , "matches":4, "goals": 10}
]

a.reduce([0,0]){|sum,h|[sum.first+h["goals"],sum.last+h["matches"]]}.reduce{|sum,m|sum.to_f/m}

sevenmaxis

def absent_numbers(array)
  [array.each, array.reverse_each].each_with_object([]) do |result, iterator|
    iterator.reduce do |prev_, next_|
      if (prev_ - next_).abs > 1
        result << (prev_ > next_ ? prev_ - 1 : next_ - 1)
        break
      end
      next_ # it's very important
    end
  end