public T Max()
{
if (root == null)
{
throw new Exception("The tree is empty!");
}
AvlNode pos = root;
while (pos.Right != null)
{
pos = pos.Right;
}
return(pos.Value);
}
internal AvlNode <T> Insert(AvlNode <T> node, T value)
{
if (node == null)
{
return(new AvlNode <T>(value));
}
if (Compare(node.Value, value) > 0)
{
node.Left = Insert((AvlNode <T>)node.Left, value);
}
else
{
node.Right = Insert((AvlNode <T>)node.Right, value);
}
return(Balance(node));
}
/// <summary>
/// Removes a node that has no children.
/// </summary>
/// <param name="node">The node.</param>
protected override void RemoveNodeWithNoChild(BinarySearchTree <TKey, TValue> .Node node)
{
if (node == null)
{
return;
}
AvlNode parent = node.Parent as AvlNode;
base.RemoveNodeWithNoChild(node);
if (parent != null)
{
this.Balance(parent);
}
}
private static AvlNode RotateRight(AvlNode y)
{
var x = y.Left;
var temp = x.Right;
// rotation
x.Right = y;
y.Left = temp;
// update height
y.Height = Math.Max(Height(y.Left), Height(y.Right)) + 1;
x.Height = Math.Max(Height(x.Left), Height(x.Right)) + 1;
// new root
return(x);
}
private static AvlNode RotateLeft(AvlNode x)
{
var y = x.Right;
var temp = y.Left;
// rotation
y.Left = x;
x.Right = temp;
// update height
x.Height = Math.Max(Height(x.Left), Height(x.Right)) + 1;
y.Height = Math.Max(Height(y.Left), Height(y.Right)) + 1;
// new root
return(y);
}
public TValue Pop()
{
if (_root == null)
{
return(default(TValue));
}
AvlNode currentNode = _root;
while (currentNode.Left != null)
{
currentNode = currentNode.Left;
}
return(Delete(currentNode.Key, currentNode.Value));
}
private void InsertBalance(AvlNode node, int balance)
{
while (node != null)
{
balance = (node.Balance += balance);
if (balance == 0)
{
return;
}
else if (balance == 2)
{
if (node.Left.Balance == 1)
{
RotateRight(node);
}
else
{
RotateLeftRight(node);
}
return;
}
else if (balance == -2)
{
if (node.Right.Balance == -1)
{
RotateLeft(node);
}
else
{
RotateRightLeft(node);
}
return;
}
AvlNode parent = node.Parent;
if (parent != null)
{
balance = parent.Left == node ? 1 : -1;
}
node = parent;
}
}
public AvlNode AddOrReplace([NotNull] TKey key, TValue value)
{
var compare = key.CompareTo(this.key);
if (compare == 0)
{
this.value = value;
return(this);
}
if (compare < 0)
{
if (this.left != null)
{
this.left = this.left.AddOrReplace(key, value);
// Check whether rebalance is necessary and update height
var node = Rebalance(this);
node.height = CalculateHeight(node);
return(node);
}
else
{
this.left = new AvlNode(key, value);
this.height = 2;
return(this);
}
}
else
{
if (this.right != null)
{
this.right = this.right.AddOrReplace(key, value);
var node = Rebalance(this);
node.height = CalculateHeight(node);
return(node);
}
else
{
this.right = new AvlNode(key, value);
this.height = 2;
return(this);
}
}
}
public static int AssertBalanced(AvlNode V)
{
if (V == null)
{
return(0);
}
int a = AssertBalanced(V.Left);
int b = AssertBalanced(V.Right);
if (((a - b) != V.Balance) || (Math.Abs(a - b) >= 2))
{
throw new InvalidOperationException();
}
return(1 + Math.Max(a, b));
}
/// <summary>
/// Inserts the specified segment to the tree.
/// </summary>
/// <param name="segment">The segment.</param>
/// <exception cref="System.ArgumentNullException">The segment is null.</exception>
public void Insert(SweepLineSegment segment)
{
if (segment == null)
{
throw new ArgumentNullException(nameof(segment));
}
if (this.root == null)
{
this.root = new AvlNode {
Key = segment, Value = segment, Balance = 0
};
this.currentNode = this.root;
this.nodeCount++;
this.version++;
return;
}
AvlNode node = this.SearchNodeForInsertion(segment) as AvlNode;
if (node == null)
{
return;
}
if (this.Comparer.Compare(segment, node.Key) < 0)
{
node.LeftChild = new AvlNode {
Key = segment, Value = segment, Parent = node, Balance = 0
};
node.Balance = -1;
this.currentNode = node.LeftChild;
}
else
{
node.RightChild = new AvlNode {
Key = segment, Value = segment, Parent = node, Balance = 0
};
node.Balance = 1;
this.currentNode = node.RightChild;
}
this.Balance(node);
this.nodeCount++;
this.version++;
}
/// <summary>
/// Inserts the specified segment to the tree.
/// </summary>
/// <param name="segment">The segment.</param>
/// <exception cref="System.ArgumentNullException">The segment is null.</exception>
public void Insert(SweepLineSegment segment)
{
if (segment == null)
{
throw new ArgumentNullException("segment", "The segment is null.");
}
if (_root == null)
{
_root = new AvlNode {
Key = segment, Value = segment, Balance = 0
};
_currentNode = _root;
_nodeCount++;
_version++;
return;
}
AvlNode node = SearchNodeForInsertion(segment) as AvlNode;
if (node == null)
{
return;
}
if (_comparer.Compare(segment, node.Key) < 0)
{
node.LeftChild = new AvlNode {
Key = segment, Value = segment, Parent = node, Balance = 0
};
node.Balance = -1;
_currentNode = node.LeftChild;
}
else
{
node.RightChild = new AvlNode {
Key = segment, Value = segment, Parent = node, Balance = 0
};
node.Balance = 1;
_currentNode = node.RightChild;
}
Balance(node);
_nodeCount++;
_version++;
}
private static AvlNode FixWithRotateRight(AvlNode N)
{
var L = N.Left;
var LR = L.Right;
switch (L.Balance)
{
case 1:
N.Balance = 0;
L.Balance = 0;
N.Left = LR;
L.Right = N;
return(L);
case 0:
N.Balance = 1;
L.Balance = -1;
N.Left = LR;
L.Right = N;
return(L);
case -1:
L.Right = LR.Left;
N.Left = LR.Right;
var nLRBalance = (sbyte)-LR.Balance;
if (nLRBalance > 0)
{
L.Balance = nLRBalance;
N.Balance = 0;
}
else
{
L.Balance = 0;
N.Balance = nLRBalance;
}
LR.Balance = 0;
LR.Left = L;
LR.Right = N;
return(LR);
}
return(null);
}
private static AvlNode FixWithRotateLeft(AvlNode N)
{
var R = N.Right;
var RL = R.Left;
switch (R.Balance)
{
case -1:
N.Balance = 0;
R.Balance = 0;
N.Right = RL;
R.Left = N;
return(R);
case 0:
N.Balance = -1;
R.Balance = 1;
N.Right = RL;
R.Left = N;
return(R);
case 1:
R.Left = RL.Right;
N.Right = RL.Left;
var nRLBalance = (sbyte)-RL.Balance;
if (nRLBalance > 0)
{
R.Balance = 0;
N.Balance = nRLBalance;
}
else
{
R.Balance = nRLBalance;
N.Balance = 0;
}
RL.Balance = 0;
RL.Right = R;
RL.Left = N;
return(RL);
}
return(null);
}
// ******************************************************************
public bool MoveNext()
{
if (!_convexHull.IsInitDone)
{
return(false);
}
if (_currentQuadrant == null)
{
_currentQuadrant = _convexHull._q1;
_currentNode = _currentQuadrant.GetFirstNode();
}
else
{
for (;;)
{
AvlNode <PolygonPoint> nextNode = _currentNode.GetNextNode();
if (nextNode == null)
{
if (_currentQuadrant == _convexHull._q4)
{
return(false);
}
_currentQuadrant = _currentQuadrant.GetNextQuadrant();
nextNode = _currentQuadrant.GetFirstNode();
if (nextNode.Item == _currentNode.Item)
{
_currentNode = nextNode;
return(MoveNext());
}
}
else
{
_currentNode = nextNode;
break;
}
}
}
return(true);
}
private static void Description <TKey>(StringBuilder builder, AvlNode <TKey, TKey> node)
{
if (node != null)
{
builder.Append(node.Key);
for (int i = 0; i < node.Balance; i++)
{
builder.Append("+");
}
for (int i = node.Balance; i < 0; i++)
{
builder.Append("-");
}
if (node.Left != null || node.Right != null)
{
builder.Append(":{");
if (node.Left == null)
{
builder.Append("~");
}
else
{
Description(builder, node.Left);
}
builder.Append(",");
if (node.Right == null)
{
builder.Append("~");
}
else
{
Description(builder, node.Right);
}
builder.Append("}");
}
}
}
public static int Count <TKey>(this AvlNode <TKey, TKey> source)
{
int count = 1;
AvlNode <TKey, TKey> left = source.Left;
AvlNode <TKey, TKey> right = source.Right;
if (right != null)
{
count += Count(left);
}
if (right != null)
{
count += Count(right);
}
return(count);
}
private AvlNode findMax(final AvlNode arg)
{
AvlNode t = arg;
if (t == null)
{
{ /*$goal 0 reachable*/ }
return(t);
}
while (t.right != null)
{
{ /*$goal 1 reachable*/ }
t = t.right;
}
{ /*$goal 2 reachable*/ }
return(t);
}
public Enumerator(SmallDictionary <K, V> dict)
: this()
{
AvlNode root = dict._root;
if (root != null)
{
// left == right only if both are nulls
if (root.Left == root.Right)
{
_next = dict._root;
}
else
{
_stack = new Stack <AvlNode>(dict.HeightApprox());
_stack.Push(dict._root);
}
}
}
private static void Replace(AvlNode target, AvlNode source)
{
AvlNode left = source.Left;
AvlNode right = source.Right;
target.Balance = source.Balance;
target.Key = source.Key;
target.Value = source.Value;
target.Left = left;
target.Right = right;
if (left != null)
{
left.Parent = target;
}
if (right != null)
{
right.Parent = target;
}
}
private AvlNode Insert(AvlNode root, int value)
{
if (root == null)
{
return(new AvlNode(value));
}
if (value > root.GetValue())
{
root.SetRightChild(Insert(root.GetRightChild(), value));
}
else
{
root.SetLeftChild(Insert(root.GetLeftChild(), value));
}
SetHeight(root);
return(Balance(root));
}
private void Insert(T x, ref AvlNode root)
{
//！！看清执行顺序很重要
if (root == null)
{
root = new AvlNode(x);
}
else if (x.CompareTo(root.date) < 0)//左子树插入，左孩子高度肯定大于右孩子
{
//总是先Insert，更新height后，调整
Insert(x, ref root.left);
//用GetHeight是为了避免出现指向null的状况，因为没有null.height = -1
if (GetHeight(root.left) - GetHeight(root.right) == 2)//平衡度
{
if (x.CompareTo(root.left.date) < 0)
{
LL(ref root);
}
else
{
LR(ref root);
}
}
}
else//右子树插入，右孩子高度肯定大于左孩子
{
Insert(x, ref root.right);
if (GetHeight(root.right) - GetHeight(root.left) == 2)
{
if (x.CompareTo(root.right.date) > 0)
{
RR(ref root);
}
else
{
RL(ref root);
}
}
}
root.height = max(GetHeight(root.left), GetHeight(root.right)) + 1;//每次都是优先insert，再一级一级往上计算height，插入玩每个节点的height都是正确的
}
/// <summary>
/// Inserts the specified key/value pair to the tree.
/// </summary>
/// <param name="key">The key of the element to insert.</param>
/// <param name="value">The value of the element to insert. The value can be <c>null</c> for reference types.</param>
/// <exception cref="System.ArgumentNullException">The key is null.</exception>
/// <exception cref="System.ArgumentException">An element with the same key already exists in the tree.</exception>
public override void Insert(TKey key, TValue value)
{
if (key == null)
{
throw new ArgumentNullException("key", "The key is null.");
}
if (_root == null)
{
_root = new AvlNode {
Key = key, Value = value, Height = 0, Balance = 0
};
_nodeCount++;
_version++;
return;
}
AvlNode node = SearchNodeForInsertion(key) as AvlNode;
if (node == null)
{
throw new ArgumentException("An element with the same key already exists in the tree.", "key");
}
if (_comparer.Compare(key, node.Key) < 0)
{
node.LeftChild = new AvlNode {
Key = key, Value = value, Parent = node, Height = 0, Balance = 0
};
}
else
{
node.RightChild = new AvlNode {
Key = key, Value = value, Parent = node, Height = 0, Balance = 0
};
}
Balance(node);
_nodeCount++;
_version++;
}
/// <summary>
/// Inserts the specified key/value pair to the tree.
/// </summary>
/// <param name="key">The key of the element to insert.</param>
/// <param name="value">The value of the element to insert. The value can be <c>null</c> for reference types.</param>
/// <exception cref="System.ArgumentNullException">The key is null.</exception>
/// <exception cref="System.ArgumentException">An element with the same key already exists in the tree.</exception>
public override void Insert(TKey key, TValue value)
{
if (key == null)
{
throw new ArgumentNullException(nameof(key));
}
if (this.root == null)
{
this.root = new AvlNode {
Key = key, Value = value, Height = 0, Balance = 0
};
this.nodeCount++;
this.version++;
return;
}
AvlNode node = this.SearchNodeForInsertion(key) as AvlNode;
if (node == null)
{
throw new ArgumentException(CollectionMessages.KeyExists, nameof(key));
}
if (this.Comparer.Compare(key, node.Key) < 0)
{
node.LeftChild = new AvlNode {
Key = key, Value = value, Parent = node, Height = 0, Balance = 0
};
}
else
{
node.RightChild = new AvlNode {
Key = key, Value = value, Parent = node, Height = 0, Balance = 0
};
}
this.Balance(node);
this.nodeCount++;
this.version++;
}
public bool MoveNext()
{
switch (_action)
{
case Action.Right:
_current = _right;
while (_current.Left != null)
{
_current = _current.Left;
}
_right = _current.Right;
_action = _right != null ? Action.Right : Action.Parent;
return(true);
case Action.Parent:
while (_current.Parent != null)
{
AvlNode previous = _current;
_current = _current.Parent;
if (_current.Left == previous)
{
_right = _current.Right;
_action = _right != null ? Action.Right : Action.Parent;
return(true);
}
}
_action = Action.End;
return(false);
default:
return(false);
}
}
private void BalanceAfterInsertion(AvlNode node, int balance)
{
while (node != null)
{
balance = (node.Balance += balance);
switch (balance)
{
case 0:
return;
case 2:
if (node.Left.Balance == 1)
{
RotateRight(node);
}
else
{
RotateLeftRight(node);
}
return;
case -2:
if (node.Right.Balance == -1)
{
RotateLeft(node);
}
else
{
RotateRightLeft(node);
}
return;
}
AvlNode parent = node.Parent;
if (parent != null)
{
balance = ((parent.Left == node) ? 1 : (-1));
}
node = parent;
}
}
private void HandleInsert(AvlNode node, AvlNode parent, K key, V value, bool add)
{
Node currentNode = node;
do
{
if (CompareKeys(currentNode.Key, key))
{
if (add)
{
throw new InvalidOperationException();
}
currentNode.Value = value;
return;
}
currentNode = currentNode.Next;
} while (currentNode != null);
AddNode(node, parent, key, value);
}
public bool Search(TKey key, out TValue value)
{
AvlNode avlNode = _root;
while (avlNode != null)
{
if (_comparer.Compare(key, avlNode.Key) < 0)
{
avlNode = avlNode.Left;
continue;
}
if (_comparer.Compare(key, avlNode.Key) > 0)
{
avlNode = avlNode.Right;
continue;
}
value = avlNode.Value;
return(true);
}
value = default(TValue);
return(false);
}
//Source: https://www.geeksforgeeks.org/iterative-method-to-find-height-of-binary-tree/
private int TreeHeight(AvlNode <int> node)
{
if (node == null)
{
return(0);
}
var q = new Queue <AvlNode <int> >();
q.Enqueue(node);
int height = 0;
while (true)
{
var nodeCount = q.Count();
if (nodeCount == 0)
{
return(height);
}
height++;
// Dequeue all nodes of current level and Enqueue all
// nodes of next level
while (nodeCount > 0)
{
var newNode = q.Dequeue();
if (newNode.LeftChild != null)
{
q.Enqueue((AvlNode <int>)newNode.LeftChild);
}
if (newNode.RightChild != null)
{
q.Enqueue((AvlNode <int>)newNode.RightChild);
}
nodeCount--;
}
}
}
private IEnumerator <T> GetEnumerator(AvlNode node)
{
if (node == null)
{
yield break;
}
var leftTree = GetEnumerator(node.Left);
while (leftTree.MoveNext())
{
yield return(leftTree.Current);
}
yield return(node.Key);
var rightTree = GetEnumerator(node.Right);
while (rightTree.MoveNext())
{
yield return(rightTree.Current);
}
}
internal AvlNode <T> Balance(AvlNode <T> node)
{
FixHeight(node);
var balanceFactor = GetBalanceFactor(node);
switch (balanceFactor)
{
case 2:
if (GetBalanceFactor((AvlNode <T>)node.Right) < 0)
{
node.Right = RotateToRight((AvlNode <T>)node.Right);
}
return(RotateToLeft(node));
case -2:
if (GetBalanceFactor((AvlNode <T>)node.Left) > 0)
{
node.Left = RotateToLeft((AvlNode <T>)node.Left);
}
return(RotateToRight(node));
}
return(node);
}
private boolean repOK_isOrdered(AvlNode n)
{
if (n==null)
return true;
int min = repOK_isOrderedMin(n);
int max = repOK_isOrderedMax(n);
return repOK_isOrdered(n, min, max);
}
private boolean repOK_isOrdered(AvlNode n, int min, int max)
{
if ((n.element<min ) || (n.element>max))
return false;
if (n.left != null) {
if (!repOK_isOrdered(n.left, min, n.element))
return false;
}
if (n.right != null) {
if (!repOK_isOrdered(n.right, n.element, max))
return false;
}
return true;
}
private int repOK_isOrderedMax(AvlNode n)
{
AvlNode curr = n;
while (curr.right!=null) {
curr = curr.right;
}
return curr.element;
}
private int repOK_isOrderedMin(AvlNode n)
{
AvlNode curr = n;
while (curr.left!=null) {
curr = curr.left;
}
return curr.element;
}