public RBNode(string data, RBNode parent = null)
{
this.data = data;
_color = RBColor.Red;
right = left = null;
this.parent = parent;
}
internal RBNode(RBColor color, T item, RBNode <T> p, RBNode <T> left, RBNode <T> right)
{
this.color = color;
this.parent = p;
this.left = left;
this.right = right;
this.Item = item;
}
/// <summary>
/// 右部分木のエントリー削除に伴う赤黒木の修正(4つのパターン
/// 戻り値は修正された木。auzに付加情報を返す
/// </summary>
private Node BalanceR(Node t, Trio aux)
{
//BalanceLと左右対称
if (!aux.change)
{
return(t);
}
else if (IsB(t.lst) && IsR(t.lst.rst))
{
RBColor rb = t.color;
t = RotateLR(t);
t.color = rb;
t.rst.color = RBColor.B;
aux.change = false;
}
else if (IsB(t.lst) && IsR(t.lst.lst))
{
RBColor rb = t.color;
t = RotateR(t);
t.color = rb;
t.lst.color = t.rst.color = RBColor.B;
aux.change = false;
}
else if (IsB(t.lst))
{
RBColor rb = t.color;
t.color = RBColor.B;
t.lst.color = RBColor.R;
aux.change = rb == RBColor.B;
}
else if (IsR(t.lst))
{
t = RotateR(t);
t.color = RBColor.B;
t.rst.color = RBColor.R;
t.rst = BalanceR(t.rst, aux);
aux.change = false;
}
else
{
throw new Exception("(L) This program is buggy");
}
return(t);
}
/// <summary>
/// 左部分木のエントリー削除に伴う赤黒木の修正(4つのパターン
/// 戻り値は修正された木。auxに付加情報を返す
/// </summary>
private Node BalanceL(Node t, Trio aux)
{
if (!aux.change)
{
return(t);
}
else if (IsB(t.rst) && IsR(t.rst.lst))
{
RBColor rb = t.color;
t = RotateRL(t);
t.color = rb;
t.lst.color = RBColor.B; //左側に黒が追加されて修正
aux.change = false;
}
else if (IsB(t.rst) && IsR(t.rst.rst))
{
RBColor rb = t.color;
t = RotateL(t);
t.color = rb;
t.lst.color = t.rst.color = RBColor.B; //左側に黒が追加されて修正
aux.change = false;
}
else if (IsB(t.rst))
{
RBColor rb = t.color;
t.color = RBColor.B;
t.rst.color = RBColor.R;
aux.change = rb == RBColor.B; //tが黒の場合は黒が減るので修正フラグを立て木を遡る(親で何とかする
}
else if (IsR(t.rst))
{
t = RotateL(t);
t.color = RBColor.B;
t.lst.color = RBColor.R;
t.lst = BalanceL(t.lst, aux); //再帰は必ず一段で終わる
aux.change = false;
}
else
{
throw new Exception("(L) This program is buggy");
}
return(t);
}
internal RBNode(RBColor color)
{
this.color = color;
}
public RBNode(RBColor color, K key, V value)
{
this.color = color;
this.key = key;
this.value = value;
}
private void Delete(NodeRB node)
{
NodeRB DeletingNode = node;
NodeRB ZamenaItem;
RBColor FirstColor = node.Color;
bool?myPosition;
if (node.Parent == null)
{
myPosition = null;
}
else if (node.Parent.Left == node)
{
myPosition = false;
}
else
{
myPosition = true;
}
//1
if (node.Left == null && node.Right == null)
{
if (myPosition == null)
{
node.Key = null;
node.Sum = 0;
}
if (myPosition == false)
{
node.Parent.Left = null;
}
if (myPosition == true)
{
node.Parent.Right = null;
}
node.Parent = null;
}
//2
if (node.Left != null && node.Right == null)
{
if (myPosition == null)
{
Tree = node.Left;
node.Left.Parent = null;
//node.Left = null;
}
if (myPosition == false)
{
node.Parent.Left = node.Left;
node.Left.Parent = node.Parent;
//node.Parent = null;
//node.Left = null;
}
if (myPosition == true)
{
node.Parent.Right = node.Left;
node.Left.Parent = node.Parent;
//node.Parent = null;
//node.Left = null;
}
}
if (node.Left == null && node.Right != null)
{
if (myPosition == null)
{
Tree = node.Right;
node.Right.Parent = null;
//node.Right = null;
}
if (myPosition == false)
{
node.Parent.Left = node.Right;
node.Right.Parent = node.Parent;
//node.Parent = null;
//node.Right = null;
}
if (myPosition == true)
{
node.Parent.Right = node.Right;
node.Right.Parent = node.Parent;
node.Parent = null;
node.Right = null;
}
}
//3
if (node.Left != null && node.Right != null)
{
ZamenaItem = FindMin(node.Right);
node.Key = ZamenaItem.Key;
node.Sum = ZamenaItem.Sum;
if (node.Color == RBColor.Red)
{
node.Color = ZamenaItem.Color;
Delete(ZamenaItem);
return;
}
if (node.Color == RBColor.Black && ZamenaItem.Color == RBColor.Red)
{
node.Color = RBColor.Black;
Delete(ZamenaItem);
return;
}
if (node.Color == RBColor.Black && ZamenaItem.Color == RBColor.Black)
{
DeleteBalanser(node);
}
}
}
/*
* Delete node z and replace it with y. If z has only one child we just replace z with
* that child. If z has two children then y should be z's successor.
* */
private void RBDelete(Node z)
{
Node x;
//First, set y equal to z
Node y = z;
/*
* We want to store z's original color so when we move a node
* into z's postion and the value of yOriginalColor is black then we call
* RBDeleteFixup.
*/
RBColor yOriginalColor = y.color;
/*
* The first two if statements cover when z just has one child. If
* so, just replace z with the child
*/
if (z.left == NIL.Instance())
{
x = z.right;
RBTransplant(z, z.right);
}
else if (z.right == NIL.Instance())
{
x = z.left;
RBTransplant(z, z.left);
}
else
{
/*
* z has two children. First find the successor (the smallest key
* that is larger than z. Move it into z's position by setting it's
* parent to z and re-assign child nodes.
*/
y = RBTreeMinimum(z.right);
yOriginalColor = y.color;
x = y.right;
if (y.parent == z)
{
x.parent = y;
}
else
{
RBTransplant(y, y.right);
y.right = z.right;
y.right.parent = y;
}
RBTransplant(z, y);
y.left = z.left;
y.left.parent = y;
y.color = z.color;
}
/*
* If node y was black, several problems may arise which RBDeleteFixup will fix.
* */
if (yOriginalColor == RBColor.BLACK)
{
RBDeleteFixup(x);
}
}
public Node next = null; //一つ大きい値のkeyを持つNode
public Node(RBColor color, K key, Node parent)
{
this.color = color;
this.key = key;
this.parent = parent;
}
