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Questions tagged [red-black-tree]

A red-black tree is a type of self-balancing binary search tree, a data structure used in computing science, typically used to implement associative arrays.

From Wikipedia, Red–black tree:

A red-black tree is a special type of binary tree, used in computer science to organize pieces of comparable data, such as text fragments or numbers.

The leaf nodes of red-black trees do not contain data. These leaves need not be explicit in computer memory — a null child pointer can encode the fact that this child is a leaf — but it simplifies some algorithms for operating on red-black trees if the leaves really are explicit nodes. To save memory, sometimes a single sentinel node performs the role of all leaf nodes; all references from internal nodes to leaf nodes then point to the sentinel node.

Red-black trees, like all binary search trees, allow efficient in-order traversal in the fashion, Left-Root-Right, of their elements. The search-time results from the traversal from root to leaf, and therefore a balanced tree, having the least possible tree height, results in O(log n) search time.

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Trie vs red-black tree: which is better in space and time？

Tries and red-black trees are very efficient for storing strings. Which has better time complexity? How about space complexity?
xuh5156
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Deletion in Left Leaning Red Black Trees

I am learning about Left Leaning Red Black Trees. In the deletion algorithm peresented in the paper, if the key matches for a node and the right subtree is NULL for that node, then that node is deleted. But there may be a left subtree as well which…
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why does qmap uses skiplist instead ob rb-tree?

I wounder why does QMap realised over skiplist data-structure and not rb-tree? There is very interesting SO thread about concurrency data-structs and skip-list benefits over rb-tree, pros and cons. It is indeed VERY interesing dialog with helpfull…
sohel
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How are red-black trees isomorphic to 2-3-4 trees?

I have a basic understanding of both red black trees and 2-3-4 trees and how they maintain the height balance to make sure that the worst case operations are O(n logn). But, I am not able to understand this text from Wikipedia 2-3-4 trees are an…
Lazer
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Why Red Black Trees always having nil nodes as their leaf nodes and what is it implies?

I don't know why we need the NIL node as a leaf node in Red-Black Trees. Can anyone give an explanation about its purpose?
user9888628
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Deleting a whole subtree of a red-black tree would keep its properties?

I'm currently implementing a red-black tree data structure to perform some optimizations for an application. In my application, at a given point I need to remove all elements less than or equal to a given value (you can assume that the elements are…
Phil
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Trouble understanding libstdc++'s Red-black tree iterators

I'm trying to implement iterators for a Ternary Search Tree, and because TSTs are very similar to BSTs, I thought I'd look at libstdc++'s implementation for said iterators. The idea is to iterate through all tree nodes without modifying the tree or…
Ron
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How to deal with duplicates in red-black trees?

So I've been(so far unsuccessfully) trying to make my red-black tree implementation work consistently with duplicates, but it seems to always be missing that small something, so here I am. I tried make the tree lean to one side, but It didn't seem…
jonas rudzionis
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std::map Known-Position Erase Amortized Complexity And Number of Red-Black Tree Recolorings

The complexity of std::map::erase(iterator) is amortized O(1) (see here, for example). While the standard library does not dictate implementations, this de-facto means that the number of rebalancing operations needed for a red-black tree is…
Ami Tavory
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Is there something like mulitiSet in JavaScript?

I know that JavaScript now has sets, but I wonder if there is something to realize the function of multiSet, or if there is some framework that has the functions of multiset which I really need a lot. Or I have to code it by myself to do the…
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Does inserting/erasing an element from a std::map modify the iteration sequence?

Say I have the following code: typedef std::map< int, std::string >::iterator Iterator; Iterator iter = myMap.begin(); while (iter != myMap.end()) { Iterator current = iter; ++iter; maybeDeleteElement( current ) // may call…
Dominic Gurto
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Where can I find a simple red-black tree implementation?

It's not easy to find red-black tree implementations on the net, especially for learning. Where can I find a simple red-black tree implementation (C# preferred)?
user541686
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Strange results when plotting (Cormen) Red-black tree insert

I implemented in Red-Black trees in Python according to the pseudo code in Cormen's Introduction to Algorithms. I wanted to see in my own eyes that my insert is really O(logn) so I plotted the time it takes to insert n=1, 10, 20, ..., 5000 nodes…
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Which is easier to implement: 2-3-4 Tree or Red-Black Tree?

The textbook I'm learning from (Lafore) presents Red-Black Trees first, and does not include any pseudo-code, although the associated algorithms as presented seems fairly complex, with many unique cases. Next he presents 2-3-4 Trees which seem to me…
The111
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Red Black Tree deletion algorithm

From "Introduction to Algorithms 2nd edition" I got this deletion algorithm: /* RB-DELETE(T, z) 1 if left[z] = nil[T] or right[z] = nil[T] 2 then y ← z 3 else y ← TREE-SUCCESSOR(z) 4 if left[y] ≠ nil[T] 5 then x ←…
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