Talk:AVL tree/C++: Difference between revisions
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I tested the elaborate code versus the shorter C++ version (on the main page) with the following results: |
I tested the elaborate code versus the shorter C++ version (on the main page) with the following results: |
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<pre> |
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AVLtree insertions took: 00:00:02.5097816 |
AVLtree insertions took: 00:00:02.5097816 |
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Set insertions took: 00:00:00.0080027 |
Set insertions took: 00:00:00.0080027 |
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</pre> |
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Clearly, AVLtree is more like O(N<sup>2</sup>) or worse than O(log N). This is because it descends the tree during rotations (to adjust the balance factor). Set is clearly very fast at O(log N). The test was for 10000 insertions. If 100000 or 1000000 insertions are used Set rips through it but AVLtree stalls the machine.[[User:NNcNannara|NNcNannara]] ([[User talk:NNcNannara|talk]]) 12:45, 15 July 2016 (UTC) |
Clearly, AVLtree is more like O(N<sup>2</sup>) or worse than O(log N). This is because it descends the tree during rotations (to adjust the balance factor). Set is clearly very fast at O(log N). The test was for 10000 insertions. If 100000 or 1000000 insertions are used Set rips through it but AVLtree stalls the machine.[[User:NNcNannara|NNcNannara]] ([[User talk:NNcNannara|talk]]) 12:45, 15 July 2016 (UTC) |
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Revision as of 12:08, 16 July 2016
The algorithms started out life in Pascal in a book called "Data Structures and Program Design" by Robert L Kruse. These were top/down (i.e. root to leaf) recursive algorithms without parent pointers. In 2006, the algorithms were made bottom/up (i.e. leaf to root) and the recursion was abolished (using parent pointers). These algorithms may be compared to the red/black set algorithms of STL. NNcNannara (talk) 12:30, 13 July 2016 (UTC)
I tested the elaborate code versus the shorter C++ version (on the main page) with the following results:
AVLtree insertions took: 00:00:02.5097816 Set insertions took: 00:00:00.0080027
Clearly, AVLtree is more like O(N2) or worse than O(log N). This is because it descends the tree during rotations (to adjust the balance factor). Set is clearly very fast at O(log N). The test was for 10000 insertions. If 100000 or 1000000 insertions are used Set rips through it but AVLtree stalls the machine.NNcNannara (talk) 12:45, 15 July 2016 (UTC)