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avglvltree: use rotateleft/right for delete

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git-svn-id: trunk@36139 -
This commit is contained in:
mattias 2012-03-17 21:11:41 +00:00
parent 55c2b15076
commit 23abaf2eae
1 changed files with 20 additions and 171 deletions
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191
components/lazutils/avglvltree.pas
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@ -834,9 +834,7 @@ end;
procedure TAvgLvlTree.BalanceAfterDelete(ANode: TAvgLvlTreeNode);
var
OldParent, OldRight, OldRightLeft, OldLeft, OldLeftRight,
OldRightLeftLeft, OldRightLeftRight, OldLeftRightLeft, OldLeftRightRight
: TAvgLvlTreeNode;
OldParent, OldRight, OldRightLeft, OldLeft, OldLeftRight: TAvgLvlTreeNode;
begin
while ANode<>nil do begin
if ((ANode.Balance=+1) or (ANode.Balance=-1)) then exit;
@ -856,20 +854,7 @@ begin
if (OldRight.Balance>=0) then begin
// OldRight.Balance is 0 or -1
// rotate ANode,OldRight 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;
RotateLeft(ANode);
ANode.Balance:=(1-OldRight.Balance); // toggle 0 and 1
Dec(OldRight.Balance);
ANode:=OldRight;
@ -889,26 +874,8 @@ begin
OldRightLeftLeft OldRightLeftRight
}
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;
RotateRight(OldRight);
RotateLeft(ANode);
if (OldRightLeft.Balance<=0) then
ANode.Balance:=0
else
@ -926,28 +893,15 @@ begin
OldLeft:=ANode.Left;
if (OldLeft.Balance<=0) then begin
// rotate OldLeft,ANode 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;
RotateRight(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
= rotate OldRightLeft,OldRight right
and then rotate ANode,OldRightLeft left
= rotate OldLeft,OldLeftRight left
and then rotate OldLeft,ANode right
OldParent OldParent
| |
ANode OldLeftRight
@ -959,26 +913,8 @@ begin
OldLeftRightLeft OldLeftRightRight
}
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;
RotateLeft(OldLeft);
RotateRight(ANode);
if (OldLeftRight.Balance>=0) then
ANode.Balance:=0
else
@ -1001,7 +937,7 @@ begin
OldParent:=ANode.Parent;
while (OldParent<>nil) do begin
if (OldParent.Left=ANode) then begin
// Node is left son
// Node is left child
dec(OldParent.Balance);
if (OldParent.Balance=0) then exit;
if (OldParent.Balance=-1) then begin
@ -1020,25 +956,6 @@ begin
\ /
OldRight OldRight }
RotateRight(OldParent);
{OldRight:=ANode.Right;
OldParentParent:=OldParent.Parent;
if (OldParentParent<>nil) then begin
// OldParent has GrandParent. GrandParent gets new child
if (OldParentParent.Left=OldParent) then
OldParentParent.Left:=ANode
else
OldParentParent.Right:=ANode;
end else begin
// OldParent was fRoot node. New fRoot node
fRoot:=ANode;
end;
ANode.Parent:=OldParentParent;
ANode.Right:=OldParent;
OldParent.Parent:=ANode;
OldParent.Left:=OldRight;
if (OldRight<>nil) then
OldRight.Parent:=OldParent;}
ANode.Balance:=0;
OldParent.Balance:=0;
end else begin
@ -1058,31 +975,6 @@ begin
OldRight:=ANode.Right;
RotateLeft(ANode);
RotateRight(OldParent);
{OldParentParent:=OldParent.Parent;
OldRightLeft:=OldRight.Left;
OldRightRight:=OldRight.Right;
if (OldParentParent<>nil) then begin
// OldParent has GrandParent. GrandParent gets new child
if (OldParentParent.Left=OldParent) then
OldParentParent.Left:=OldRight
else
OldParentParent.Right:=OldRight;
end else begin
// OldParent was fRoot node. new fRoot node
fRoot:=OldRight;
end;
OldRight.Parent:=OldParentParent;
OldRight.Left:=ANode;
OldRight.Right:=OldParent;
ANode.Parent:=OldRight;
ANode.Right:=OldRightLeft;
OldParent.Parent:=OldRight;
OldParent.Left:=OldRightRight;
if (OldRightLeft<>nil) then
OldRightLeft.Parent:=ANode;
if (OldRightRight<>nil) then
OldRightRight.Parent:=OldParent;}
if (OldRight.Balance<=0) then
ANode.Balance:=0
else
@ -1095,7 +987,7 @@ begin
end;
exit;
end else begin
// Node is right son
// Node is right child
Inc(OldParent.Balance);
if (OldParent.Balance=0) then exit;
if (OldParent.Balance=+1) then begin
@ -1114,24 +1006,6 @@ begin
/ \
OldLeft OldLeft }
RotateLeft(OldParent);
{OldLeft:=ANode.Left;
OldParentParent:=OldParent.Parent;
if (OldParentParent<>nil) then begin
// Parent has GrandParent. GrandParent gets new child
if(OldParentParent.Left=OldParent) then
OldParentParent.Left:=ANode
else
OldParentParent.Right:=ANode;
end else begin
// OldParent was fRoot node. new fRoot node
fRoot:=ANode;
end;
ANode.Parent:=OldParentParent;
ANode.Left:=OldParent;
OldParent.Parent:=ANode;
OldParent.Right:=OldLeft;
if (OldLeft<>nil) then
OldLeft.Parent:=OldParent;}
ANode.Balance:=0;
OldParent.Balance:=0;
end else begin
@ -1151,32 +1025,6 @@ begin
OldLeft:=ANode.Left;
RotateRight(ANode);
RotateLeft(OldParent);
{OldParentParent:=OldParent.Parent;
OldLeftLeft:=OldLeft.Left;
OldLeftRight:=OldLeft.Right;
if (OldParentParent<>nil) then begin
// OldParent has GrandParent. GrandParent gets new child
if (OldParentParent.Left=OldParent) then
OldParentParent.Left:=OldLeft
else
OldParentParent.Right:=OldLeft;
end else begin
// OldParent was fRoot node. new fRoot node
fRoot:=OldLeft;
end;
OldLeft.Parent:=OldParentParent;
OldLeft.Left:=OldParent;
OldLeft.Right:=ANode;
ANode.Parent:=OldLeft;
ANode.Left:=OldLeftRight;
OldParent.Parent:=OldLeft;
OldParent.Right:=OldLeftLeft;
if (OldLeftLeft<>nil) then
OldLeftLeft.Parent:=OldParent;
if (OldLeftRight<>nil) then
OldLeftRight.Parent:=ANode;}
if (OldLeft.Balance>=0) then
ANode.Balance:=0
else
@ -1231,7 +1079,8 @@ begin
end;
procedure TAvgLvlTree.Delete(ANode: TAvgLvlTreeNode);
var OldParent, OldLeft, OldRight, Successor, OldSuccParent, OldSuccLeft,
var
OldParent, OldLeft, OldRight, Successor, OldSuccParent, OldSuccLeft,
OldSuccRight: TAvgLvlTreeNode;
OldBalance: integer;
begin
@ -1244,11 +1093,11 @@ begin
if (OldParent<>nil) then begin
// Node has parent
if (OldParent.Left=ANode) then begin
// Node is left Son of OldParent
// Node is left child of OldParent
OldParent.Left:=nil;
Inc(OldParent.Balance);
end else begin
// Node is right Son of OldParent
// Node is right child of OldParent
OldParent.Right:=nil;
Dec(OldParent.Balance);
end;
@ -1262,7 +1111,7 @@ begin
exit;
end;
if (ANode.Right=nil) then begin
// Left is only son
// Left is only child
// and because DelNode is AVL, Right has no childrens
// replace DelNode with Left
OldLeft:=ANode.Left;
@ -1285,7 +1134,7 @@ begin
exit;
end;
if (ANode.Left=nil) then begin
// Right is only son
// Right is only child
// and because DelNode is AVL, Left has no childrens
// replace DelNode with Right
OldRight:=ANode.Right;
@ -1327,7 +1176,7 @@ begin
Successor.Right:=OldRight;
OldRight.Parent:=Successor;
end else begin
// Successor is right son of ANode
// Successor is right child of ANode
ANode.Parent:=Successor;
Successor.Right:=ANode;
end;
@ -1892,7 +1741,7 @@ var
LeftDepth: SizeInt;
RightDepth: SizeInt;
begin
// test left son
// test left child
if Left<>nil then begin
if Left.Parent<>Self then
E('Left.Parent<>Self');
@ -1900,7 +1749,7 @@ begin
E('Compare(Left.Data,Data)>0');
Left.ConsistencyCheck(Tree);
end;
// test right son
// test right child
if Right<>nil then begin
if Right.Parent<>Self then
E('Right.Parent<>Self');