Module: Partitions::IntegerPartitions

Included in:
Integer
Defined in:
lib/partitions/integer_partitions.rb

Instance Method Summary collapse

Instance Method Details

#partitions ⇒ Object 



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# File 'lib/partitions/integer_partitions.rb', line 4

def partitions
  n = self
  if n < 0
    raise ArgumentError, "n should be greater than or equal to 0"
  end

  a = Array.new(n + 1, 0)
  k = 2
  a[1] = 0
  a[2] = n
  while k != 1 do
    y = a[k] - 1
    k = k - 1
    x = a[k] + 1

    while x <= y do
      a[k] = x
      y = y - x
      k = k  + 1
    end

    a[k] = x + y

    if block_given?
      yield a.values_at(1..k)
    else
      p a.values_at(1..k)
    end
  end
end