mirror of
https://gitlab.com/freepascal.org/lazarus/lazarus.git
synced 2025-05-31 01:47:43 +02:00
avglvltree: replaced recursion with simple loop
git-svn-id: trunk@36134 -
This commit is contained in:
mattias
parent
c41894692e
commit
ef5ef38048
@ -830,135 +830,134 @@ var
|
||||
OldRightLeftLeft, OldRightLeftRight, OldLeftRightLeft, OldLeftRightRight
|
||||
: TAvgLvlTreeNode;
|
||||
begin
|
||||
if (ANode=nil) then exit;
|
||||
if ((ANode.Balance=+1) or (ANode.Balance=-1)) then exit;
|
||||
OldParent:=ANode.Parent;
|
||||
if (ANode.Balance=0) then begin
|
||||
// Treeheight has decreased by one
|
||||
if (OldParent<>nil) then begin
|
||||
while ANode<>nil do begin
|
||||
if ((ANode.Balance=+1) or (ANode.Balance=-1)) then exit;
|
||||
OldParent:=ANode.Parent;
|
||||
if (ANode.Balance=0) then begin
|
||||
// Treeheight has decreased by one
|
||||
if (OldParent=nil) then
|
||||
exit;
|
||||
if(OldParent.Left=ANode) then
|
||||
Inc(OldParent.Balance)
|
||||
else
|
||||
Dec(OldParent.Balance);
|
||||
BalanceAfterDelete(OldParent);
|
||||
end;
|
||||
exit;
|
||||
end;
|
||||
if (ANode.Balance=+2) then begin
|
||||
// Node is overweighted to the right
|
||||
OldRight:=ANode.Right;
|
||||
if (OldRight.Balance>=0) then begin
|
||||
// OldRight.Balance is 0 or -1
|
||||
// rotate left
|
||||
OldRightLeft:=OldRight.Left;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldRight
|
||||
ANode:=OldParent;
|
||||
end else if (ANode.Balance=+2) then begin
|
||||
// Node is overweighted to the right
|
||||
OldRight:=ANode.Right;
|
||||
if (OldRight.Balance>=0) then begin
|
||||
// OldRight.Balance is 0 or -1
|
||||
// rotate left
|
||||
OldRightLeft:=OldRight.Left;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldRight
|
||||
else
|
||||
OldParent.Right:=OldRight;
|
||||
end else
|
||||
fRoot:=OldRight;
|
||||
ANode.Parent:=OldRight;
|
||||
ANode.Right:=OldRightLeft;
|
||||
OldRight.Parent:=OldParent;
|
||||
OldRight.Left:=ANode;
|
||||
if (OldRightLeft<>nil) then
|
||||
OldRightLeft.Parent:=ANode;
|
||||
ANode.Balance:=(1-OldRight.Balance); // toggle 0 and 1
|
||||
Dec(OldRight.Balance);
|
||||
ANode:=OldRight;
|
||||
end else begin
|
||||
// OldRight.Balance=-1
|
||||
// double rotate right left
|
||||
OldRightLeft:=OldRight.Left;
|
||||
OldRightLeftLeft:=OldRightLeft.Left;
|
||||
OldRightLeftRight:=OldRightLeft.Right;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldRightLeft
|
||||
else
|
||||
OldParent.Right:=OldRightLeft;
|
||||
end else
|
||||
fRoot:=OldRightLeft;
|
||||
ANode.Parent:=OldRightLeft;
|
||||
ANode.Right:=OldRightLeftLeft;
|
||||
OldRight.Parent:=OldRightLeft;
|
||||
OldRight.Left:=OldRightLeftRight;
|
||||
OldRightLeft.Parent:=OldParent;
|
||||
OldRightLeft.Left:=ANode;
|
||||
OldRightLeft.Right:=OldRight;
|
||||
if (OldRightLeftLeft<>nil) then
|
||||
OldRightLeftLeft.Parent:=ANode;
|
||||
if (OldRightLeftRight<>nil) then
|
||||
OldRightLeftRight.Parent:=OldRight;
|
||||
if (OldRightLeft.Balance<=0) then
|
||||
ANode.Balance:=0
|
||||
else
|
||||
OldParent.Right:=OldRight;
|
||||
end else
|
||||
fRoot:=OldRight;
|
||||
ANode.Parent:=OldRight;
|
||||
ANode.Right:=OldRightLeft;
|
||||
OldRight.Parent:=OldParent;
|
||||
OldRight.Left:=ANode;
|
||||
if (OldRightLeft<>nil) then
|
||||
OldRightLeft.Parent:=ANode;
|
||||
ANode.Balance:=(1-OldRight.Balance); // toggle 0 and 1
|
||||
Dec(OldRight.Balance);
|
||||
BalanceAfterDelete(OldRight);
|
||||
ANode.Balance:=-1;
|
||||
if (OldRightLeft.Balance>=0) then
|
||||
OldRight.Balance:=0
|
||||
else
|
||||
OldRight.Balance:=+1;
|
||||
OldRightLeft.Balance:=0;
|
||||
ANode:=OldRightLeft;
|
||||
end;
|
||||
end else begin
|
||||
// OldRight.Balance=-1
|
||||
// double rotate right left
|
||||
OldRightLeft:=OldRight.Left;
|
||||
OldRightLeftLeft:=OldRightLeft.Left;
|
||||
OldRightLeftRight:=OldRightLeft.Right;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldRightLeft
|
||||
// Node.Balance=-2
|
||||
// Node is overweighted to the left
|
||||
OldLeft:=ANode.Left;
|
||||
if (OldLeft.Balance<=0) then begin
|
||||
// rotate right
|
||||
OldLeftRight:=OldLeft.Right;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldLeft
|
||||
else
|
||||
OldParent.Right:=OldLeft;
|
||||
end else
|
||||
fRoot:=OldLeft;
|
||||
ANode.Parent:=OldLeft;
|
||||
ANode.Left:=OldLeftRight;
|
||||
OldLeft.Parent:=OldParent;
|
||||
OldLeft.Right:=ANode;
|
||||
if (OldLeftRight<>nil) then
|
||||
OldLeftRight.Parent:=ANode;
|
||||
ANode.Balance:=(-1-OldLeft.Balance); // toggle 0 and -1
|
||||
Inc(OldLeft.Balance);
|
||||
ANode:=OldLeft;
|
||||
end else begin
|
||||
// OldLeft.Balance = 1
|
||||
// double rotate left right
|
||||
OldLeftRight:=OldLeft.Right;
|
||||
OldLeftRightLeft:=OldLeftRight.Left;
|
||||
OldLeftRightRight:=OldLeftRight.Right;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldLeftRight
|
||||
else
|
||||
OldParent.Right:=OldLeftRight;
|
||||
end else
|
||||
fRoot:=OldLeftRight;
|
||||
ANode.Parent:=OldLeftRight;
|
||||
ANode.Left:=OldLeftRightRight;
|
||||
OldLeft.Parent:=OldLeftRight;
|
||||
OldLeft.Right:=OldLeftRightLeft;
|
||||
OldLeftRight.Parent:=OldParent;
|
||||
OldLeftRight.Left:=OldLeft;
|
||||
OldLeftRight.Right:=ANode;
|
||||
if (OldLeftRightLeft<>nil) then
|
||||
OldLeftRightLeft.Parent:=OldLeft;
|
||||
if (OldLeftRightRight<>nil) then
|
||||
OldLeftRightRight.Parent:=ANode;
|
||||
if (OldLeftRight.Balance>=0) then
|
||||
ANode.Balance:=0
|
||||
else
|
||||
OldParent.Right:=OldRightLeft;
|
||||
end else
|
||||
fRoot:=OldRightLeft;
|
||||
ANode.Parent:=OldRightLeft;
|
||||
ANode.Right:=OldRightLeftLeft;
|
||||
OldRight.Parent:=OldRightLeft;
|
||||
OldRight.Left:=OldRightLeftRight;
|
||||
OldRightLeft.Parent:=OldParent;
|
||||
OldRightLeft.Left:=ANode;
|
||||
OldRightLeft.Right:=OldRight;
|
||||
if (OldRightLeftLeft<>nil) then
|
||||
OldRightLeftLeft.Parent:=ANode;
|
||||
if (OldRightLeftRight<>nil) then
|
||||
OldRightLeftRight.Parent:=OldRight;
|
||||
if (OldRightLeft.Balance<=0) then
|
||||
ANode.Balance:=0
|
||||
else
|
||||
ANode.Balance:=-1;
|
||||
if (OldRightLeft.Balance>=0) then
|
||||
OldRight.Balance:=0
|
||||
else
|
||||
OldRight.Balance:=+1;
|
||||
OldRightLeft.Balance:=0;
|
||||
BalanceAfterDelete(OldRightLeft);
|
||||
end;
|
||||
end else begin
|
||||
// Node.Balance=-2
|
||||
// Node is overweighted to the left
|
||||
OldLeft:=ANode.Left;
|
||||
if (OldLeft.Balance<=0) then begin
|
||||
// rotate right
|
||||
OldLeftRight:=OldLeft.Right;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldLeft
|
||||
ANode.Balance:=+1;
|
||||
if (OldLeftRight.Balance<=0) then
|
||||
OldLeft.Balance:=0
|
||||
else
|
||||
OldParent.Right:=OldLeft;
|
||||
end else
|
||||
fRoot:=OldLeft;
|
||||
ANode.Parent:=OldLeft;
|
||||
ANode.Left:=OldLeftRight;
|
||||
OldLeft.Parent:=OldParent;
|
||||
OldLeft.Right:=ANode;
|
||||
if (OldLeftRight<>nil) then
|
||||
OldLeftRight.Parent:=ANode;
|
||||
ANode.Balance:=(-1-OldLeft.Balance); // toggle 0 and -1
|
||||
Inc(OldLeft.Balance);
|
||||
BalanceAfterDelete(OldLeft);
|
||||
end else begin
|
||||
// OldLeft.Balance = 1
|
||||
// double rotate left right
|
||||
OldLeftRight:=OldLeft.Right;
|
||||
OldLeftRightLeft:=OldLeftRight.Left;
|
||||
OldLeftRightRight:=OldLeftRight.Right;
|
||||
if (OldParent<>nil) then begin
|
||||
if (OldParent.Left=ANode) then
|
||||
OldParent.Left:=OldLeftRight
|
||||
else
|
||||
OldParent.Right:=OldLeftRight;
|
||||
end else
|
||||
fRoot:=OldLeftRight;
|
||||
ANode.Parent:=OldLeftRight;
|
||||
ANode.Left:=OldLeftRightRight;
|
||||
OldLeft.Parent:=OldLeftRight;
|
||||
OldLeft.Right:=OldLeftRightLeft;
|
||||
OldLeftRight.Parent:=OldParent;
|
||||
OldLeftRight.Left:=OldLeft;
|
||||
OldLeftRight.Right:=ANode;
|
||||
if (OldLeftRightLeft<>nil) then
|
||||
OldLeftRightLeft.Parent:=OldLeft;
|
||||
if (OldLeftRightRight<>nil) then
|
||||
OldLeftRightRight.Parent:=ANode;
|
||||
if (OldLeftRight.Balance>=0) then
|
||||
ANode.Balance:=0
|
||||
else
|
||||
ANode.Balance:=+1;
|
||||
if (OldLeftRight.Balance<=0) then
|
||||
OldLeft.Balance:=0
|
||||
else
|
||||
OldLeft.Balance:=-1;
|
||||
OldLeftRight.Balance:=0;
|
||||
BalanceAfterDelete(OldLeftRight);
|
||||
OldLeft.Balance:=-1;
|
||||
OldLeftRight.Balance:=0;
|
||||
ANode:=OldLeftRight;
|
||||
end;
|
||||
end;
|
||||
end;
|
||||
end;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user