--- Ukesoppgave om huffmantr?r
proc HuffmanLeaves(tree, chars):
  if v.symbol == null:
    HuffmanLeaves(v.left, chars)
    HuffmanLeaves(v.right, chars)
  else:
    add (v.symbol, v.freq) to chars
  return chars

--- Ukesoppgave om heap
class Heap:
  Heap(x):
    this.head = Node(x)
    this.size = 1

  class Node:
    Node(x):
      this.elem = x
      this.left = null
      this.right = null
      this.parent = null

    method bubbleDown():
      if this.left == null:
        return
      minChild = this.left
      if this.right != null and this.right.elem < minChild.elem:
        minChild = this.right
      if this.elem > minChild.elem:
        this.elem, minChild.elem = minChild.elem, this.elem
        minChild.bubbleDown()

    method bubbleUp():
      if this.parent == null:
        return
      if this.parent.elem > this.elem:
        this.parent.elem, this.elem = this.elem, this.parent.elem
        this.parent.bubbleUp()

  method insert(x):
    node = Node(x)
    this.addLast(node)
    node.bubbleUp()

  method removeMin():
    min = this.head.elem
    oldLast = this.removeLast()
    this.head.elem = oldLast.elem
    this.head.bubbleDown()

  method addLast(newNode):
    this.size += 1
    path = binary representation of this.size
    node = this.head
    for digit in path[1..]:
      if digit == 0:
        if node.left != null:
          node = node.left
        else:
          node.left = newNode
      else:
        if node.right != null:
          node = node.right
        else:
          node.right = newNode

  method removeLast():
    path = binary representation of this.size
    node = this.head
    for digit in path[1..]:
      if digit == 0:
        node = node.left
      else:
        node = node.right
    if path[path.length - 1] == 0:
      node.parent.left = null
    else:
      node.parent.right = null
    this.size -= 1      
    return node