http://icpc2010.honiden.nii.ac.jp/domestic-contest/problems#section_C

gistfile1.rb

$tetra_num = Hash.new{|h,k| h[k] = k*(k+1)*(k+2)/6}

def tetra_array(n)
  i,t = 1,[]
  while n >= $tetra_num[i]
    t << $tetra_num[i]
    i += 1
  end
  t
end

def answer(n, t)
  i = 1
  while i <= n
    t.repeated_combination(i).each do |c|
      m = c.inject(:+)
      if n == m
        return c
      end
    end
    i += 1
  end
end

inputs = [40,14,5,165,120,103,106,139]

inputs.each do |i|
  t = tetra_array(i)
  a = answer(i,t)
  b = answer(i,t.select{|x| x.odd?})
  puts "#{a.size} #{b.size}"
end