| 1 | /* $Id: kAvlRemoveBestFit.h 7 2008-02-04 02:08:02Z bird $ */
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| 2 | /** @file
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| 3 | * kAvlTmpl - Templated AVL Trees, Remove Best Fitting Node.
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| 4 | */
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| 5 |
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| 6 | /*
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| 7 | * Copyright (c) 1999-2007 knut st. osmundsen <bird-src-spam@anduin.net>
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| 8 | *
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| 9 | * This file is part of kStuff.
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| 10 | *
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| 11 | * kStuff is free software; you can redistribute it and/or
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| 12 | * modify it under the terms of the GNU Lesser General Public
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| 13 | * License as published by the Free Software Foundation; either
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| 14 | * version 2.1 of the License, or (at your option) any later version.
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| 15 | *
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| 16 | * kStuff is distributed in the hope that it will be useful,
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| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 19 | * Lesser General Public License for more details.
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| 20 | *
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| 21 | * You should have received a copy of the GNU Lesser General Public
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| 22 | * License along with kStuff; if not, write to the Free Software
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| 23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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| 24 | *
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| 25 | *
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| 26 | * As a special exception, since this is a source file and not a header
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| 27 | * file, you are granted permission to #include this file as you wish
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| 28 | * without this in itself causing the resulting program or whatever to be
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| 29 | * covered by the LGPL license. This exception does not however invalidate
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| 30 | * any other reasons why the resulting program/whatever should not be
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| 31 | * covered the LGPL or GPL.
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| 32 | */
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| 33 |
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| 34 |
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| 35 | /**
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| 36 | * Finds the best fitting node in the tree for the given Key value and removes the node.
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| 37 | *
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| 38 | * @returns Pointer to the removed node.
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| 39 | * @param pRoot Pointer to the AVL-tree root structure.
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| 40 | * @param Key The Key of which is to be found a best fitting match for..
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| 41 | * @param fAbove K_TRUE: Returned node is have the closest key to Key from above.
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| 42 | * K_FALSE: Returned node is have the closest key to Key from below.
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| 43 | *
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| 44 | * @remark This implementation uses GetBestFit and then Remove and might therefore
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| 45 | * not be the most optimal kind of implementation, but it reduces the complexity
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| 46 | * code size, and the likelyhood for bugs.
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| 47 | */
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| 48 | KAVL_DECL(KAVLNODE *) KAVL_FN(RemoveBestFit)(KAVLROOT *pRoot, KAVLKEY Key, KBOOL fAbove)
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| 49 | {
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| 50 | /*
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| 51 | * If we find anything we'll have to remove the node and return it.
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| 52 | * Now, if duplicate keys are allowed we'll remove a duplicate before
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| 53 | * removing the in-tree node as this is way cheaper.
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| 54 | */
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| 55 | KAVLNODE *pNode = KAVL_FN(GetBestFit)(pRoot, Key, fAbove);
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| 56 | if (pNode != NULL)
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| 57 | {
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| 58 | #ifdef KAVL_EQUAL_ALLOWED
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| 59 | KAVL_WRITE_LOCK(pRoot); /** @todo the locking isn't quite sane here. :-/ */
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| 60 | if (pNode->mpList != KAVL_NULL)
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| 61 | {
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| 62 | KAVLNODE *pRet = KAVL_GET_POINTER(&pNode->mpList);
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| 63 | KAVL_SET_POINTER_NULL(&pNode->mpList, &pRet->mpList);
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| 64 | KAVL_LOOKTHRU_INVALIDATE_NODE(pRoot, pNode, pNode->mKey);
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| 65 | KAVL_WRITE_UNLOCK(pRoot);
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| 66 | return pRet;
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| 67 | }
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| 68 | KAVL_WRITE_UNLOCK(pRoot);
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| 69 | #endif
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| 70 | pNode = KAVL_FN(Remove)(pRoot, pNode->mKey);
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| 71 | }
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| 72 | return pNode;
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| 73 | }
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| 74 |
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