Heap in Ruby

heap.rb

class Heap
  def initialize(*elems)
    @h= heapify(elems)
  end
  def inspect
    return '(empty)' if @h.empty?
    @h
      .group_by.with_index{ Math.log2(_2+1).to_i }
      .map{ |l,vs| vs.join(' ') }
      .join("\n")
  end
  def insert(v)
    # Place new value at the end,
    # then bubble up.
    @h << v
    return if @h.size == 1
    i, ip= @h.size-1, parent(@h.size-1)
    n, p= @h[i], @h[ip]
    return if i == 0
    while n > p
      @h[i], @h[ip]= @h[ip], @h[i]
      i, ip= ip, parent(ip)
      break if ip.nil?
      n, p= @h[i], @h[ip]
    end
  end
  def remove()
    # Remove first element;
    # move last element to root;
    # bubble down root.
    return @h.delete_at(0) if @h.size == 1
    res= @h.first
    @h[0]= @h.delete_at(@h.size- 1)
    i, il, ir= 0, left(0), right(0)
    n, l, r= @h[i], @h[il], @h[ir]
    while n < (l||n) || n < (r||n)
      j= l >= (r||l) ? il : ir
      @h[i], @h[j]= @h[j], @h[i]
      i, il, ir= j, left(j), right(j)
      n, l, r= @h[i], @h[il], @h[ir]
    end
    res
  end
  def size()
    @h.size
  end
  private
  def heapify(elems)
    h= elems
    i= (h.size-2)/2
    il, ir= left(i), right(i)
    n, l, r= h[i], h[il], h[ir]
    while i >= 0
      while n < (l||n) || n < (r||n)
        # bubble down: swap node with larger child
        # until heap condition is met
        j= l >= (r||l) ? il : ir
        h[i], h[j] = h[j], h[i]
        i, il, ir= j, left(j), right(j)
        n, l, r= h[i], h[il], h[ir]
      end
      # continue with next node, to the left/upwards
      i, il, ir= i-1, left(i-1), right(i-1)
      n, l, r= h[i], h[il], h[ir]
    end
    h
  end
  def parent(i)
    return nil if i == 0
    ((i-1)/2).to_i
  end
  def left(i)
    i*2+1
  end
  def right(i)
    i*2+2
  end
end

#####

def sep()
  puts '-'* 10
end

h= Heap.new(1,2,3,5,6,7,8)
p h
sep

h.insert(10)
p h
sep

puts h.remove()
p h
sep

elems= h.size.times.map{ h.remove() }
p h
p elems
sep

10.times
  .map{ rand(20) }
  .each{ h.insert(_1) }
p h
sep

h= Heap.new("a", "b", "c", "x")
p h
sep