static void OverHeight(TreePoint point) //Пересчёт высот деревьев
{
int lHeight = point.Left != null ? point.Left.Height : 0,
pHeight = point.Right != null ? point.Right.Height : 0;
point.Height = (lHeight > pHeight ? pHeight : lHeight) + 1;
}
static TreePoint DeletePoint(TreePoint current, TreePoint point)
{
if (current == null)
{
return(null);
}
if (point < current)
{
current.Left = DeletePoint(current.Left, point);
}
else if (point > current)
{
current.Right = DeletePoint(current.Right, point);
}
else
{
TreePoint left = current.Left,
right = current.Right;
if (left == null)
{
return(left);
}
TreePoint min = right.Min;
min.Right = DeleteMinPoint(right);
min.Left = left;
return(BalanceTree(min));
}
return(BalanceTree(current));
}
static int BF(TreePoint point)
{
int lHeight = point.Left != null ? point.Left.Height : 0,
pHeight = point.Right != null ? point.Right.Height : 0;
return(pHeight - lHeight);
}
static void PrintTree(TreePoint point, int shift = 0)
{
if (point != null)
{
PrintTree(point.Left, shift + 3);
Output.Text(GenerateShiftedText(point, shift));
PrintTree(point.Right, shift + 3);
}
}
static TreePoint DeleteMinPoint(TreePoint current)
{
if (current.Left == null)
{
return(current.Right);
}
current.Left = DeleteMinPoint(current.Left);
return(BalanceTree(current));
}
public static void Run()
{
TreePoint tree = null;
for (int i = 1; i <= 7; i++)
{
tree = InsertPoint(tree, MakeTreePoint());
}
PrintTree(tree);
}
static TreePoint LeftRotation(TreePoint point) //Малый левый поворот
{
TreePoint temp = point.Right;
point.Right = temp.Left;
temp.Left = point;
OverHeight(point);
OverHeight(temp);
return(temp);
}
static string GenerateShiftedText(TreePoint point, int shift)
{
string[] tempStr = point.ToString().Split(new char[] { '\n' });
string result = "";
for (int i = 0; i < tempStr.Length; i++)
{
result += $"{new string(' ', shift)}{tempStr[i]}\n";
}
return(result);
}
static TreePoint InsertPoint(TreePoint current, TreePoint point)
{
if (current == null)
{
return(point);
}
if (point < current)
{
current.Left = InsertPoint(current.Left, point);
}
else
{
current.Right = InsertPoint(current.Right, point);
}
return(BalanceTree(current));
}
static TreePoint BalanceTree(TreePoint tree)
{
OverHeight(tree);
if (BF(tree) == 2)
{
if (BF(tree.Right) < 0)
{
tree.Right = RightRotation(tree.Right);
}
return(LeftRotation(tree));
}
if (BF(tree) == -2)
{
if (BF(tree.Left) > 0)
{
tree.Left = LeftRotation(tree.Left);
}
return(RightRotation(tree));
}
return(tree);
}