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67 lines
1.9 KiB
Markdown
67 lines
1.9 KiB
Markdown
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# GoLLRB
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GoLLRB is a Left-Leaning Red-Black (LLRB) implementation of 2-3 balanced binary
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search trees in Go Language.
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## Overview
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As of this writing and to the best of the author's knowledge,
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Go still does not have a balanced binary search tree (BBST) data structure.
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These data structures are quite useful in a variety of cases. A BBST maintains
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elements in sorted order under dynamic updates (inserts and deletes) and can
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support various order-specific queries. Furthermore, in practice one often
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implements other common data structures like Priority Queues, using BBST's.
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2-3 trees (a type of BBST's), as well as the runtime-similar 2-3-4 trees, are
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the de facto standard BBST algoritms found in implementations of Python, Java,
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and other libraries. The LLRB method of implementing 2-3 trees is a recent
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improvement over the traditional implementation. The LLRB approach was
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discovered relatively recently (in 2008) by Robert Sedgewick of Princeton
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University.
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GoLLRB is a Go implementation of LLRB 2-3 trees.
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## Maturity
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GoLLRB has been used in some pretty heavy-weight machine learning tasks over many gigabytes of data.
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I consider it to be in stable, perhaps even production, shape. There are no known bugs.
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## Installation
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With a healthy Go Language installed, simply run `go get github.com/petar/GoLLRB/llrb`
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## Example
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package main
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import (
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"fmt"
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"github.com/petar/GoLLRB/llrb"
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)
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func lessInt(a, b interface{}) bool { return a.(int) < b.(int) }
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func main() {
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tree := llrb.New(lessInt)
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tree.ReplaceOrInsert(1)
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tree.ReplaceOrInsert(2)
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tree.ReplaceOrInsert(3)
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tree.ReplaceOrInsert(4)
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tree.DeleteMin()
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tree.Delete(4)
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c := tree.IterAscend()
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for {
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u := <-c
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if u == nil {
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break
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}
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fmt.Printf("%d\n", int(u.(int)))
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}
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}
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## About
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GoLLRB was written by [Petar Maymounkov](http://pdos.csail.mit.edu/~petar/).
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Follow me on [Twitter @maymounkov](http://www.twitter.com/maymounkov)!
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