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Questions tagged [tree-rotation]

Tree rotation is an operation on a binary tree that changes the structure without interfering with the order of the elements.

Tree rotation is an operation on a binary tree that changes the structure without interfering with the order of the elements. A tree rotation moves one node up in the tree and one node down. It is used to change the shape of the tree, and in particular to decrease its height by moving smaller subtrees down and larger subtrees up, resulting in improved performance of many tree operations.

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Is it always possible to turn one BST into another using tree rotations?

Given a set of values, it's possible for there to be many different possible binary search trees that can be formed from those values. For example, for the values 1, 2, and 3, there are five BSTs we can make from those values: 1 1 2 …
templatetypedef
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Prove maximum number of rotations for two trees to become equal

In the book Introduction To Algorithms - A Creative Approach, Question 4.24: Let T1, and T2 be two arbitrary trees, each having n nodes. Prove that it is sufficient to apply at most 2n rotations to T1, so that it becomes equal to T2. For binary…
Guocheng
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Binary tree transformation using rotations

While i was studying for midterm about binary trees, i found a statement that any arbitrary n-node binary tree can be transformed into any other n-node binary tree with at most 2*n-2 rotations. Is there any proof for that? I found some kind of proof…
fhuseynli
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Is it always possible to turn one BST into another using at most O(n) tree rotations?

This earlier question asks whether it's always possible to turn one BST for a set of values into another BST for the same set of values purely using tree rotations (the answer is yes). However, is it always possible to do this using at most O(n)…
Kian Sulieman
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Algorithms for converting from complete-binary-search-tree order to sorted order and vice versa

This question is similar to Sorted list to complete BST array representation but perhaps more specifically focused. This question could be used to solve Inserting node dynamically in Complete Binary Search Tree. Consider a complete binary tree…
Quuxplusone
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Extra Cases in AVL Trees

AVL Trees seem to have four kinds of transformations: Left-Left, Left-Right, Right-Left, and Right-Right. However, it seems like there could be other circumstances as well. I submit this as Left-Balanced: Neither Left nor Right rotations can…
Mark Karavan
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AVL trees insertion and deletion

I would like to know whether I am applying the following insertion and deletion operations correctly on an AVL tree: 62 / \ 44 78 / \ \ …
freshman_2021
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May binary search tree get broken by rotation?

I'm learning algorithms now, and while implementing red-black tree insertion I came up to the idea described in the question's header. This takes place when equal value nodes are involved. Let's start with a simple example tree, where left children…
Denis Seletkov
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AVL tree Rotation problems

I've been facing a very weird problem with an AVL tree implementation. Given the code below, I can only run it with no right rotations, since that if I do, I have a crash. I already tried debugging, deleting files and remaking the project, and…
inblank
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Max. number of rotations while inserting a new element into n-element red black tree

What is the maximum number of rotations while inserting a new element into n-element Red Black Tree? If I'm correct, insertion that does not violate rules of RBT requries maximum of 2 rotations (2 cases). Assuming that's it, is O(1) also a correct…
Kamil Gosciminski
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Rotation in a Red Black tree

I am trying to figure out the rotation in a Red Black tree while its rebalancing is done. I understand why rotation is occurring but I don't get how it is being done. Also, what intermediate rotations like LL, RR , LR and RL are done to reach till…
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I met a problem while trying to rotate an AVL tree in C

I'm having some trouble while trying to rotate an AVL tree. I've been digging in the web the whole day and I think my code should work. I don't know why but when I test my function I lose the subtrees that should've been rotated. Can I get any…
Khalil Makhloufi
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Make binary tree lean left

So I have a binary tree implementation which looks like this struct node { struct node *left; struct node *right; }; (the actual implementation is slightly more complex as there is additional data being stored as this is for a boolean…
dangee1705
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Pointers in AVL Tree Rotation

I have trouble understanding why the below tree rotation code works. If T2 points to y.left and y.left points to x, doesn't this make the last assignment x.right = T2 equal to x.right = x? Shouldn't the pointer point to the initial T2? Node…
Marc Tim Thiemann
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Left Rotation of Binary Tree in Rust Fails to Outlive The Original

I'm attempting to implement a self-balancing binary search tree and wrote a function to replace a tree with its left rotation: struct BST<'a> { l: Option<&'a BST<'a>>, r: Option<&'a BST<'a>> } impl<'a> BST<'a> { fn left_rotate(self) ->…
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