chunk.rb

describe '#chunk' do
  def chunk(arr)
    arr.inject([]) do |chunks, elem|
      current_sequence = chunks.last || []
      if elem == current_sequence.last
        current_sequence << elem
      else
        chunks << [elem]
      end
      chunks
    end
  end

  it 'chunks an array of equal elements into an array of one array' do
    chunk([1,1]).should == [ [1,1] ]
  end

  it 'chunks an array of different elements into different arrays' do
    chunk([1,2]).should == [ [1], [2] ]
  end

  it 'chunks an array with contiguous sets of elements into an array of arrays of those sets' do
    chunk([1,1,1,2,2,1,1,2,2,2]).should == [ [1,1,1], [2,2], [1,1] , [2,2,2] ]
  end

  it 'chunks an array with an odd number of elements properly' do
    chunk([1,1,1,2,2,1,1,2,2]).should == [ [1,1,1], [2,2], [1,1] , [2,2] ]
  end
end

this is my solution:

describe '#chunk' do
  def chunk(arr)
    c = arr.cycle
    c.next
    counter = 0

    arr.inject([[]]) do |results, element|
      counter += 1
      results.last << element

      if (element != c.next && counter < arr.length)
        results << []   
      end

      results
    end  

  end

  it 'chunks an array of equal elements into an array of one array' do
    chunk([1,1]).should == [ [1,1] ]
  end

  it 'chunks an array of different elements into different arrays' do
    chunk([1,2]).should == [ [1], [2] ]
  end

  it 'chunks an array with contiguous sets of elements into an array of arrays of those sets' do
    chunk([1,1,1,2,2,1,1,2,2,2]).should == [ [1,1,1], [2,2], [1,1] , [2,2,2] ]
  end

  it 'chunks an array with an odd number of elements properly' do
    chunk([1,1,1,2,2,1,1,2,2]).should == [ [1,1,1], [2,2], [1,1] , [2,2] ]
  end
end

def chunk(arr):
    c = [[arr[0]]] if arr else [[]]
    for x in arr[1:]:
        if x in c[-1]: c[-1].append(x)
        else: c.append([x])
    return c

Totally obfuscated one-liner:

def chunk(arr)
  arr.inject([[arr.shift]]) { |c, v| c.last.include?(v) ? c.last << v : c << [v]; c }
end

Jonathan, I can't let you beat me (this is not FIFA). Here's my one-liner and it handles the case where the input is an empty array :-)

def chunk(arr)
  arr.inject([]) {|c, v| (v == (c.last || []).last) ? (c.last || []) << v : c << [v]; c}
end

Congrats, you have won the trophy. Now, you just to get better in FIFA, -D... Leandro.

On 11-09-01 2:57 PM, "thuva" ***@***.*** wrote: Jonathan, I can't let you beat me (this is not FIFA). Here's my one-liner and it handles the case where the input is an empty array :-) ``` ruby def chunk(arr) arr.inject([]) {|c, v| (v == (c.last || []).last) ? (c.last || []) << v : c << [v]; c} end ```

This email and any files transmitted with it are confidential and intended solely for the recipient(s). If you are not the named addressee you should not disseminate, distribute, copy or alter this email. Any views or opinions presented in this email are solely those of the author and might not represent those of Score Media Inc. or any of its affiliates. Warning: Although Score Media Inc. has taken reasonable precautions to ensure no viruses are present in this email, the company cannot accept responsibility for any loss or damage arising from the use of this email or attachments.