public void walkLessOrEqual(rbNode node, RbKey key)
{
if (node == null || !this.inWalk())
{
return;
}
if (node.left != null)
{
this.walkLessOrEqual(node.left, key);
if (!this.inWalk())
{
return;
}
}
var cmp = node.key.ComparedTo(key);
if (cmp == KeyComparison.KeyIsLess || cmp == KeyComparison.KeysAreEqual)
{
this.incrementCount();
this.callback(this, node.key, node.value);
if (!this.inWalk())
{
return;
}
if (node.right != null)
{
this.walkLessOrEqual(node.right, key);
}
}
}
public void walkGreaterThan(rbNode node, RbKey key)
{
if (node == null || !this.inWalk())
{
return;
}
if (node.key.ComparedTo(key) == KeyComparison.KeyIsGreater)
{
if (node.left != null)
{
this.walkGreaterThan(node.left, key);
if (!this.inWalk())
{
return;
}
}
this.incrementCount();
this.callback(this, node.key, node.value);
if (!this.inWalk())
{
return;
}
}
if (node.right != null)
{
this.walkGreaterThan(node.right, key);
}
}
public void walkAll(rbNode node)
{
if (node == null || !this.inWalk())
{
return;
}
if (node.left != null)
{
this.walkAll(node.left);
if (!this.inWalk())
{
return;
}
}
this.incrementCount();
this.callback(this, node.key, node.value);
if (!this.inWalk())
{
return;
}
if (node.right != null)
{
this.walkAll(node.right);
}
}
// insertNode adds the given key and value into the node
private rbNode insertNode(rbNode node, RbKey key, object value)
{
if (node == null)
{
this.count++;
return(newRbNode(key, value));
}
var cmp = key.ComparedTo(node.key);
switch (cmp)
{
case KeyComparison.KeyIsLess:
node.left = this.insertNode(node.left, key, value);
break;
case KeyComparison.KeyIsGreater:
node.right = this.insertNode(node.right, key, value);
break;
default:
if (this.onInsert == null)
{
node.value = value;
}
else
{
node.value = this.onInsert(key, value);
}
break;
}
return(balance(node));
}
// ceilig returns the smallest key node in the subtree rooted at x greater than or equal to the given key
private rbNode ceiling(rbNode node, RbKey key)
{
if (node == null)
{
return(null);
}
var cmp = key.ComparedTo(node.key);
switch (cmp)
{
case KeyComparison.KeysAreEqual:
return(node);
case KeyComparison.KeyIsGreater:
return(ceiling(node.right, key));
default:
var cn = ceiling(node.left, key);
if (cn != null)
{
return(cn);
}
return(node);
}
}
// floor returns the largest key node in the subtree rooted at x less than or equal to the given key
private rbNode floor(rbNode node, RbKey key)
{
if (node == null)
{
return(null);
}
var cmp = key.ComparedTo(node.key);
switch (cmp)
{
case KeyComparison.KeysAreEqual:
return(node);
case KeyComparison.KeyIsLess:
return(floor(node.left, key));
default:
var fn = floor(node.right, key);
if (fn != null)
{
return(fn);
}
return(node);
}
}
// Delete deletes the given key from the tree
public void Delete(RbKey key)
{
this.root = this.deleteNode(this.root, key);
if (this.root != null)
{
this.root.color = black;
}
}
// Insert inserts the given key and value into the tree
public void Insert(RbKey key, object value)
{
if (key != null)
{
this.root = this.insertNode(this.root, key, value);
this.root.color = black;
}
}
// newRbNode creates a new rbNode and returns its address
private rbNode newRbNode(RbKey key, object value)
{
var result = new rbNode {
key = key,
value = value,
color = red,
};
return(result);
}
// moveRedRight makes node.right or one of its children red,
// assuming that node is red and both children are black.
private rbNode moveRedRight(rbNode node)
{
colorFlip(node);
if (isRed(node.left.left))
{
node = rotateRight(node);
colorFlip(node);
}
return(node);
}
// flipColor switchs the color of the node from red to black or black to red
private void flipColor(rbNode node)
{
if (node.color == black)
{
node.color = red;
}
else
{
node.color = black;
}
}
// max finds the greatest node key including the given node
private rbNode max(rbNode node)
{
if (node != null)
{
for (; node.right != null;)
{
node = node.right;
}
}
return(node);
}
// min finds the smallest node key including the given node
private rbNode min(rbNode node)
{
if (node != null)
{
for (; node.left != null;)
{
node = node.left;
}
}
return(node);
}
// rotateRight makes a left-leaning link lean to the right
private rbNode rotateRight(rbNode node)
{
var child = node.left;
node.left = child.right;
child.right = node;
child.color = node.color;
node.color = red;
return(child);
}
// deleteMin removes the smallest key and associated value from the tree
private rbNode deleteMin(rbNode node)
{
if (node.left == null)
{
return(null);
}
if (isBlack(node.left) && !isRed(node.left.left))
{
node = moveRedLeft(node);
}
node.left = deleteMin(node.left);
return(balance(node));
}
// balance restores red-black tree invariant
private rbNode balance(rbNode node)
{
if (isRed(node.right))
{
node = rotateLeft(node);
}
if (isRed(node.left) && isRed(node.left.left))
{
node = rotateRight(node);
}
if (isRed(node.left) && isRed(node.right))
{
colorFlip(node);
}
return(node);
}
public void walkBetween(rbNode node, RbKey loKey, RbKey hiKey)
{
if (node == null || !this.inWalk())
{
return;
}
var cmpLo = (int)loKey.ComparedTo(node.key);
if (cmpLo < RbTree.zeroOrEqual)
{
if (node.left != null)
{
this.walkBetween(node.left, loKey, hiKey);
if (!this.inWalk())
{
return;
}
}
}
var cmpHi = (int)hiKey.ComparedTo(node.key);
if (cmpLo <= RbTree.zeroOrEqual && cmpHi >= RbTree.zeroOrEqual)
{
this.incrementCount();
this.callback(this, node.key, node.value);
if (!this.inWalk())
{
return;
}
}
if (cmpHi > RbTree.zeroOrEqual)
{
if (node.right != null)
{
this.walkBetween(node.right, loKey, hiKey);
}
}
}
// isRed checks if (node exists and its color is red
private bool isRed(rbNode node)
{
return(node != null && node.color == red);
}
// colorFlip switchs the color of the node and its children from red to black or black to red
private void colorFlip(rbNode node)
{
flipColor(node);
flipColor(node.left);
flipColor(node.right);
}
// deleteNode deletes the given key from the node
private rbNode deleteNode(rbNode node, RbKey key)
{
if (node == null)
{
return(null);
}
var cmp = key.ComparedTo(node.key);
if (cmp == KeyComparison.KeyIsLess)
{
if (isBlack(node.left) && !isRed(node.left.left))
{
node = moveRedLeft(node);
}
node.left = this.deleteNode(node.left, key);
}
else
{
if (cmp == KeyComparison.KeysAreEqual && this.onDelete != null)
{
var value = this.onInsert(key, node.value);
if (value != null)
{
node.value = value;
return(node);
}
}
if (isRed(node.left))
{
node = rotateRight(node);
}
if (isBlack(node.right) && !isRed(node.right.left))
{
node = moveRedRight(node);
}
if (key.ComparedTo(node.key) != KeyComparison.KeysAreEqual)
{
node.right = this.deleteNode(node.right, key);
}
else
{
if (node.right == null)
{
return(null);
}
var rm = min(node.right);
node.key = rm.key;
node.value = rm.value;
node.right = deleteMin(node.right);
rm.left = null;
rm.right = null;
this.count--;
}
}
return(balance(node));
}
// isBlack checks if (node exists and its color is black
private bool isBlack(rbNode node)
{
return(node != null && node.color == black);
}