Class: Xunch::RBTree

Inherits:
Object
  • Object
show all
Defined in:
lib/xunch/utils/rb_tree.rb,
lib/xunch/utils/rb_tree_node.rb

Defined Under Namespace

Classes: ImmutableNode, Node

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(&compare_proc) ⇒ RBTree

Creates a new tree.



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# File 'lib/xunch/utils/rb_tree.rb', line 15

def initialize(&compare_proc)
  @size = 0
  @root = nil
  @compare_proc = compare_proc
end

Instance Attribute Details

#compare_proc ⇒ Object (readonly)

The key compare proc



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# File 'lib/xunch/utils/rb_tree.rb', line 12

def compare_proc
  @compare_proc
end

#root ⇒ Object (readonly)

The tree’s root node.



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# File 'lib/xunch/utils/rb_tree.rb', line 6

def root
  @root
end

#size ⇒ Object (readonly)

The number of nodes in the tree.



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# File 'lib/xunch/utils/rb_tree.rb', line 9

def size
  @size
end

Instance Method Details

#ceiling_key(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 299

def ceiling_key(key)
  node = ceiling_node(key)
  if node == nil
    return nil
  else
    return node.key
  end
end

#ceiling_node(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 257

def ceiling_node(key)
  p = @root;
  while p != nil
    cmp = compare_key(key, p.key)
    if cmp < 0
      if p.left != nil
        p = p.left
      else
        if p == nil
          return nil
        else
          return RBTree::ImmutableNode.new(p.key,p.value)
        end
      end
    elsif cmp > 0
      if p.right != nil
        p = p.right
      else
        parent = p.parent
        ch = p
        while parent != nil && ch == parent.right
          ch = parent
          parent = parent.parent;
        end
        if parent == nil
          return nil
        else
          return RBTree::ImmutableNode.new(parent.key,parent.value)
        end
      end
    else
      if p == nil
        return nil
      else
        return RBTree::ImmutableNode.new(p.key,p.value)
      end
    end
  end

  return nil
end

#ceiling_value(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 308

def ceiling_value(key)
  node = ceiling_node(key)
  if node == nil
    return nil
  else
    return node.value
  end
end

#clear ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 75

def clear
  @size = 0
  @root = nil
end

#colorof(node) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 604

def colorof(node)
  if node != nil
    node.color
  end
end

#compare_key(key1, key2) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 616

def compare_key(key1,key2)
  if !key1.integer? || !key2.integer?
    raise "#{key1} type is #{key1.class}, #{key2} type is #{key2.class}, but need type Integer"
  end
  if @compare_proc != nil
    return @cmp_proc.call(key1, key2)
  else
    if key1 > key2
      return 1
    elsif key1 < key2
      return -1
    elsif key1 == key2
      return 0
    end
  end
end

#deletenode(p) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 391

def deletenode(p)
  @size-=1

  if p.left != nil && p.right != nil
    s = successor(p)
    p.key = s.key
    p.value = s.value
    p = s
  end

  replacement = (p.left != nil ? p.left : p.right)

  if replacement != nil
    replacement.parent = p.parent;
    if p.parent == nil
      @root = replacement
    elsif p == p.parent.left
      p.parent.left  = replacement
    else
      p.parent.right = replacement
    end

    p.left = p.right = p.parent = nil

    if p.color == :black
      fixafterdeletion(replacement)
    end
  elsif p.parent == nil
    @root = nil
  else
    if p.color == :black
      fixdfterdeletion(p)
    end
    if p.parent != nil
      if p == p.parent.left
        p.parent.left = nil
      elsif p == p.parent.right
        p.parent.right = nil
      end
      p.parent = nil
    end
  end
end

#first_key ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 94

def first_key
  p = @root;
  if p != nil
    while p.left != nil
      p = p.left
    end
  end
  p.key
end

#first_node ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 84

def first_node
  p = @root;
  if p != nil
    while p.left != nil
      p = p.left
    end
  end
  RBTree::ImmutableNode.new(p.key,p.value)
end

#first_value ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 104

def first_value
  p = @root;
  if p != nil
    while p.left != nil
      p = p.left
    end
  end
  p.value
end

#fixafterdeletion(x) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 451

def fixafterdeletion(x)
  while x != @root && colorof(x) == :black
    if x == leftof(parentof(x))
      sib = rightof(parentof(x))

      if colorof(sib) == :red
        setcolor(sib, :black)
        setcolor(parentof(x), :red)
        rotateleft(parentof(x))
        sib = rightof(parentof(x))
      end

      if colorof(leftof(sib))  == :black && colorof(rightof(sib)) == :black
        setcolor(sib, :red)
        x = parentof(x)
      else
        if colorof(rightof(sib)) == :black
          setcolor(leftof(sib), :black)
          setcolor(sib, :red)
          rotateright(sib)
          sib = rightof(parentof(x))
        end
        setcolor(sib, colorof(parentof(x)))
        setcolor(parentof(x), :black)
        setcolor(rightof(sib), :black)
        rotateleft(parentof(x))
        x = @root
      end
    else
      sib = leftof(parentof(x))

      if colorof(sib) == :red
        setcolor(sib, :black)
        setcolor(parentof(x), :red)
        rotateright(parentof(x))
        sib = leftof(parentof(x))
      end

      if colorof(rightof(sib)) == :black && colorof(leftof(sib)) == :black
        setcolor(sib, :red)
        x = parentof(x)
      else
        if colorof(leftof(sib)) == :black
          setcolor(rightof(sib), :black)
          setcolor(sib, :red)
          rotateleft(sib)
          sib = leftof(parentof(x))
        end
        setcolor(sib, colorof(parentof(x)))
        setcolor(parentof(x), :black)
        setcolor(leftof(sib), :black)
        rotateright(parentof(x))
        x = @root;
      end
    end
  end
  setcolor(x, :black);
end

#fixafterinsertion(x) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 510

def fixafterinsertion(x)
  x.color = :red

  while x != nil && x != @root && x.parent.color == :red 
    if parentof(x) == leftof(parentof(parentof(x)))
      y = rightof(parentof(parentof(x)))
      if colorof(y) == :red
        setcolor(parentof(x), :black)
        setcolor(y, :black)
        setcolor(parentof(parentof(x)), :red)
        x = parentof(parentof(x))
      else
        if x == rightof(parentof(x)) 
          x = parentof(x)
          rotateleft(x)
        end
        setcolor(parentof(x), :black);
        setcolor(parentof(parentof(x)), :red);
        rotateright(parentof(parentof(x)));
      end
    else
      y = leftof(parentof(parentof(x)))
      if colorof(y) == :red
        setcolor(parentof(x), :black)
        setcolor(y, :black)
        setcolor(parentof(parentof(x)), :red)
        x = parentof(parentof(x))
      else
        if x == leftof(parentof(x))
          x = parentof(x)
          rotateright(x)
        end
        setcolor(parentof(x), :black);
        setcolor(parentof(parentof(x)), :red);
        rotateleft(parentof(parentof(x)));
      end
    end
  end

  @root.color = :black;
end

#floor_key(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 186

def floor_key(key)
  node = floor_node(key)
  if node == nil
    return nil
  else
    return node.key
  end
end

#floor_node(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 144

def floor_node(key)
  p = @root;
  while p != nil
    cmp = compare_key(key, p.key)
    if cmp > 0
      if p.right != nil
        p = p.right
      else
        if p == nil
          return nil
        else
          return RBTree::ImmutableNode.new(p.key,p.value)
        end
      end
    elsif cmp < 0
      if p.left != nil
        p = p.left
      else
        parent = p.parent
        ch = p
        while parent != nil && ch == parent.left
          ch = parent
          parent = parent.parent;
        end
        if parent == nil
          return nil
        else
          return RBTree::ImmutableNode.new(parent.key,parent.value)
        end
      end
    else
      if p == nil
        return nil
      else
        return RBTree::ImmutableNode.new(p.key,p.value)
      end
    end
  end

  return nil
end

#floor_value(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 195

def floor_value(key)
  node = floor_node(key)
  if node == nil
    return nil
  else
    return node.value
  end
end

#get(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 70

def get(key)
  p = getnode(key);
  return (p == nil ? nil : p.value)
end

#getnode(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 435

def getnode(key)
  raise "key is nil." unless key != nil 
  p = @root;
  while p != nil
    cmp = compare_key(key, p.key)
    if cmp < 0
      p = p.left
    elsif cmp > 0
      p = p.right
    else
      return p
    end
  end
  return nil
end

#higher_key(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 353

def higher_key(key)
  node = higher_node(key)
  if node == nil
    return nil
  else
    return node.key
  end
end

#higher_node(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 317

def higher_node(key)
  p = @root;
  while p != nil
    cmp = compare_key(key, p.key)
    if cmp < 0
      if p.left != nil
        p = p.left
      else
        if p == nil
          return nil
        else
          return RBTree::ImmutableNode.new(p.key,p.value)
        end
      end
    else
      if p.right != nil
        p = p.right
      else
        parent = p.parent
        ch = p
        while parent != nil && ch == parent.right
          ch = parent
          parent = parent.parent;
        end
        if parent == nil
          return nil
        else
          return RBTree::ImmutableNode.new(parent.key,parent.value)
        end
      end
    end
  end

  return nil
end

#higher_value(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 362

def higher_value(key)
  node = higher_node(key)
  if node == nil
    return nil
  else
    return node.value
  end
end

#last_key ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 124

def last_key
  p = @root;
  if p != nil
    while p.right != nil
      p = p.right
    end
  end
  p.key
end

#last_node ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 114

def last_node
  p = @root;
  if p != nil
    while p.right != nil
      p = p.right
    end
  end
  RBTree::ImmutableNode.new(p.key,p.value)
end

#last_value ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 134

def last_value
  p = @root;
  if p != nil
    while p.right != nil
      p = p.right
    end
  end
  p.value
end

#leftof(node) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 596

def leftof(node)
  return (node == nil ? nil : node.left)
end

#lower_key(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 239

def lower_key(key)
  node = lower_node(key)
  if node == nil
    return nil
  else
    return node.key
  end
end

#lower_node(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 204

def lower_node(key)
  p = @root;
  while p != nil
    cmp = compare_key(key, p.key)
    if cmp > 0
      if p.right != nil
        p = p.right
      else
        if p == nil
          return nil
        else
          return RBTree::ImmutableNode.new(p.key,p.value)
        end
      end
    else
      if p.left != nil
        p = p.left
      else
        parent = p.parent
        ch = p
        while parent != nil && ch == parent.left
          ch = parent
          parent = parent.parent;
        end
        if parent == nil
          return nil
        else
          return RBTree::ImmutableNode.new(parent.key,parent.value)
        end
      end
    end
  end
  return nil
end

#lower_value(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 248

def lower_value(key)
  node = lower_node(key)
  if node == nil
    return nil
  else
    return node.value
  end
end

#parentof(node) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 592

def parentof(node)
  return (node == nil ? nil : node.parent)
end

#put(key, value) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 21

def put(key,value)
  tmp_node = @root
  if(tmp_node == nil)
    compare_key(key,key)
    @root = RBTree::Node.new(key,value,nil)
    @size = 1
    return value
  end
  cmp = 0
  parent = nil

  begin
    parent = tmp_node
    cmp = compare_key(key,parent.key)
    if cmp < 0
      tmp_node = tmp_node.left;
    elsif cmp > 0
      tmp_node = tmp_node.right;
    else
      return tmp_node.value = value;
    end
  end while tmp_node != nil

  node = RBTree::Node.new(key,value,parent)

  if cmp < 0
    parent.left = node
  else
    parent.right = node
  end
  
  fixafterinsertion(node)    
  @size+=1

  return value
  
end

#remove(key) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 59

def remove(key)
  p = getnode(key)
  if (p == nil)
    return nil
  end

  oldValue = p.value
  deletenode(p)
  return oldValue
end

#rightof(node) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 600

def rightof(node)
  return (node == nil ? nil : node.right)
end

#rotateleft(p) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 552

def rotateleft(p)
  if p != nil
    r = p.right
    p.right = r.left
    if r.left != nil
      r.left.parent = p
    end
    r.parent = p.parent
    if p.parent == nil
      @root = r
    elsif p.parent.left == p
      p.parent.left = r
    else
      p.parent.right = r
    end
    r.left = p
    p.parent = r
  end
end

#rotateright(p) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 572

def rotateright(p)
  if p != nil
    l = p.left
    p.left = l.right
    if l.right != nil
      l.right.parent = p
    end
    l.parent = p.parent
    if p.parent == nil
      @root = l
    elsif p.parent.right == p
      p.parent.right = l
    else 
      p.parent.left = l
    end
    l.right = p
    p.parent = l
  end
end

#setcolor(node, color) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 610

def setcolor(node, color)
  if node != nil
    node.color = color
  end 
end

#successor(t) ⇒ Object 



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# File 'lib/xunch/utils/rb_tree.rb', line 371

def successor(t)
  if t == nil
    return nil
  elsif t.right != nil
    p = t.right
    while p.left != nil
        p = p.left
    end
    return p
  else
    p = t.parent
    ch = t
    while p != nil && ch == p.right
      ch = p
      p = p.parent
    end
    return p
  end
end