avl-tree

balancing an AVL tree (C++)

穿精又带淫゛_ 提交于 2019-12-02 19:09:05
I'm having the hardest time trying to figure out how to balance an AVL tree for my class. I've got it inserting with this: Node* Tree::insert(int d) { cout << "base insert\t" << d << endl; if (head == NULL) return (head = new Node(d)); else return insert(head, d); } Node* Tree::insert(Node*& current, int d) { cout << "insert\t" << d << endl; if (current == NULL) current = new Node(d); else if (d < current->data) { insert(current->lchild, d); if (height(current->lchild) - height(current->rchild)) { if (d < current->lchild->getData()) rotateLeftOnce(current); else rotateLeftTwice(current); } }

Finding the minimum and maximum height in a AVL tree, given a number of nodes?

佐手、 提交于 2019-12-02 18:31:15
Is there a formula to calculate what the maximum and minimum height for an AVL tree, given a certain number of nodes? For example: Textbook question: What is the maximum/minimum height for an AVL tree of 3 nodes, 5 nodes, and 7 nodes? Textbook answer: The maximum/minimum height for an AVL tree of 3 nodes is 2/2, for 5 nodes is 3/3, for 7 nodes is 4/3 I don't know if they figured it out by some magic formula, or if they draw out the AVL tree for each of the given heights and determined it that way. The solution below is appropriate for working things out by hand and gaining an intuition, please

When to choose RB tree, B-Tree or AVL tree?

人走茶凉 提交于 2019-12-02 13:49:13
As a programmer when should I consider using a RB tree, B- tree or an AVL tree? What are the key points that needs to be considered before deciding on the choice? Can someone please explain with a scenario for each tree structure why it is chosen over others with reference to the key points? Take this with a pinch of salt: B-tree when you're managing more than thousands of items and you're paging them from a disk or some slow storage medium. RB tree when you're doing fairly frequent inserts, deletes and retrievals on the tree. AVL tree when your inserts and deletes are infrequent relative to

AVL Tree: Finding the key with the smallest data values in keys between two values in O(logn) time

会有一股神秘感。 提交于 2019-12-02 08:51:46
So I'm given an AVL tree. And im trying to figure out at least the pseudocode to find the key with the minimum data values among all of the keys between two values k1 and k2. This is assuming that the field data stored in each node is an integer. I want to make sure that my pseudocode runs in O(logn) time. I know that I can do it by storing an extra field in the node structure..and showing how this field can be maintained during updates, but I don't know where to go from there. Let's assume that the node structure looks like this (Java). class Node { Node left; Node right; int key; int value;

Search max value between 2 AVL nodes [duplicate]

笑着哭i 提交于 2019-12-01 11:07:50
This question is an exact duplicate of: AVL Tree: Finding the key with the smallest data values in keys between two values in O(logn) time 1 answer I have an AVL tree while each node consists of: Key Value The AVL tree is ordered by the keys . So if I got 2 keys and now I want to find the maximum value between those 2 keys. I've tried adding additional information to each node like the max value in the left subtree and same for the right subtree but I can't get the right algorithm without "losing" some nodes between. Complexity time: O(log n) worst case . What other operations do you need on

Binary search tree over AVL tree

左心房为你撑大大i 提交于 2019-11-30 14:12:55
问题 As far as I know the time complexity between AVL trees and Binary Search Trees are the same in average case, with AVLs beating BSTs in worst case scenarios. This gives me a hint that AVLs are always superior than BSTs in every possible way to interact with them, perhaps adding a little complexity when it comes to balance implementations. Is there any reason anyone should use BSTs instead of AVLs in the first place? 回答1: First, getting the best possible performance is not the ultimate goal of

More than one rotation needed to balance an AVL Tree?

雨燕双飞 提交于 2019-11-30 09:55:45
My best guess is that one rotation is always enough to balance an AVL tree when you insert or delete ONE element from an already balanced AVL tree. Is one rotation always enough? An example will help where more than one rotations are needed. PS: I count RL/LR rotations as one rotation only. For insert 1 rotation is at most. For delete the number of rotation is bounded by O(log(n)). Log(n) is the height of the tree. More explanation on AVL deletion. When you delete a node from AVL you might cause the tree unbalanced, which you have to trace back to the point where it is unbalanced. If the

More than one rotation needed to balance an AVL Tree?

一曲冷凌霜 提交于 2019-11-29 14:57:00
问题 My best guess is that one rotation is always enough to balance an AVL tree when you insert or delete ONE element from an already balanced AVL tree. Is one rotation always enough? An example will help where more than one rotations are needed. PS: I count RL/LR rotations as one rotation only. 回答1: For insert 1 rotation is at most. For delete the number of rotation is bounded by O(log(n)). Log(n) is the height of the tree. More explanation on AVL deletion. When you delete a node from AVL you

Balancing a Binary Tree (AVL)

放肆的年华 提交于 2019-11-28 23:38:57
问题 Ok, this is another one in the theory realm for the CS guys around. In the 90's I did fairly well in implementing BST's. The only thing I could never get my head around was the intricacy of the algorithm to balance a Binary Tree (AVL). Can you guys help me on this? 回答1: A scapegoat tree possibly has the simplest balance-determination algorithm to understand. If any insertion causes the new node to be too deep, it finds a node around which to rebalance, by looking at weight balance rather than

Concatenating/Merging/Joining two AVL trees

≡放荡痞女 提交于 2019-11-28 17:03:08
Assume that I have two AVL trees and that each element from the first tree is smaller then any element from the second tree. What is the most efficient way to concatenate them into one single AVL tree? I've searched everywhere but haven't found anything useful. Assuming you may destroy the input trees: remove the rightmost element for the left tree, and use it to construct a new root node, whose left child is the left tree, and whose right child is the right tree: O(log n) determine and set that node's balance factor: O(log n). In (temporary) violation of the invariant, the balance factor may