// assumption: x.Parent != null
SplayTree Zig (SplayTree x)
{
if (x.Parent.Left == x)
return RightRotate (x.Parent);
else
return LeftRotate (x.Parent);
}
// assumption: x != null && x.Right != null
// return value: node that is where rotated node (x) was
SplayTree LeftRotate(SplayTree x)
{
SplayTree y = x.Right;
x.Right = y.Left;
if (y.Left != null)
{
y.Left.Parent = x;
}
y.Parent = x.Parent;
if (x.HasParent)
{
if (x == x.Parent.Left)
{
x.Parent.Left = y;
}
else
{
x.Parent.Right = y;
}
}
y.Left = x;
x.Parent = y;
return(y);
}
// assumption: y != null && y.Left != null
// return value: node that is where rotated node (y) was
SplayTree RightRotate(SplayTree y)
{
SplayTree x = y.Left;
y.Left = x.Right;
if (x.Right != null)
{
x.Right.Parent = y;
}
x.Parent = y.Parent;
if (y.HasParent)
{
if (y == y.Parent.Left)
{
y.Parent.Left = x;
}
else
{
y.Parent.Right = x;
}
}
x.Right = y;
y.Parent = x;
return(x);
}
// assumption: x != null && x.Parent != null && x.GrandParent != null
SplayTree ZigZig (SplayTree x)
{
if (x.Parent.Left == x) {
RightRotate (x.GrandParent);
x = RightRotate (x.Parent);
} else {
LeftRotate (x.GrandParent);
x = LeftRotate (x.Parent);
}
return x;
}
// assumption: x.Parent != null
SplayTree Zig(SplayTree x)
{
if (x.Parent.Left == x)
{
return(RightRotate(x.Parent));
}
else
{
return(LeftRotate(x.Parent));
}
}
// assumption: x != null && x.Parent != null && x.GrandParent != null
bool SameDirection(SplayTree x)
{
if (x.Parent.Left == x)
{
return(x.GrandParent.Left == x.Parent);
}
else
{
return(x.GrandParent.Right == x.Parent);
}
}
// assumption: x != null && x.Parent != null && x.GrandParent != null
SplayTree ZigZag(SplayTree x)
{
if (x.Parent.Left == x)
{
x = RightRotate(x.Parent);
x = LeftRotate(x.Parent);
}
else
{
x = LeftRotate(x.Parent);
x = RightRotate(x.Parent);
}
return(x);
}
// assumption: x != null && x.Parent != null && x.GrandParent != null
SplayTree ZigZig(SplayTree x)
{
if (x.Parent.Left == x)
{
RightRotate(x.GrandParent);
x = RightRotate(x.Parent);
}
else
{
LeftRotate(x.GrandParent);
x = LeftRotate(x.Parent);
}
return(x);
}
public void SplayToRoot()
{
SplayTree x = this;
while (x.Parent != null)
{
if (x.HasGrandParent)
{
if (SameDirection(x))
{
x = ZigZig(x);
}
else
{
x = ZigZag(x);
}
}
else if (x.HasParent)
{
x = Zig(x);
}
}
}
// assumption: x != null && x.Parent != null && x.GrandParent != null
bool SameDirection (SplayTree x)
{
if (x.Parent.Left == x)
return (x.GrandParent.Left == x.Parent);
else
return (x.GrandParent.Right == x.Parent);
}
// assumption: y != null && y.Left != null
// return value: node that is where rotated node (y) was
SplayTree RightRotate (SplayTree y)
{
SplayTree x = y.Left;
y.Left = x.Right;
if (x.Right != null)
x.Right.Parent = y;
x.Parent = y.Parent;
if (y.HasParent) {
if (y == y.Parent.Left)
y.Parent.Left = x;
else
y.Parent.Right = x;
}
x.Right = y;
y.Parent = x;
return x;
}
public void AddAsRightChild(SplayTree Child)
{
this.Right = Child;
Child.Parent = this;
}
public void AddAsLeftChild(SplayTree Child)
{
this.Left = Child;
Child.Parent = this;
}
public void AddAsLeftChild (SplayTree Child)
{
this.Left = Child;
Child.Parent = this;
}
public void AddAsRightChild (SplayTree Child)
{
this.Right = Child;
Child.Parent = this;
}
// assumption: x != null && x.Parent != null && x.GrandParent != null
SplayTree ZigZag (SplayTree x)
{
if (x.Parent.Left == x) {
x = RightRotate (x.Parent);
x = LeftRotate (x.Parent);
} else {
x = LeftRotate (x.Parent);
x = RightRotate (x.Parent);
}
return x;
}
// assumption: x != null && x.Right != null
// return value: node that is where rotated node (x) was
SplayTree LeftRotate (SplayTree x)
{
SplayTree y = x.Right;
x.Right = y.Left;
if (y.Left != null)
y.Left.Parent = x;
y.Parent = x.Parent;
if (x.HasParent) {
if (x == x.Parent.Left)
x.Parent.Left = y;
else
x.Parent.Right = y;
}
y.Left = x;
x.Parent = y;
return y;
}
