Strongly connected components: Difference between revisions

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== Definition ==
== Definition ==
 
[[File:Scc.png|300px|thumb|right|Graph with marked strongly connected components]]
Let <math>G=(V,A)</math> be a [[Basic graph definitions|directed graph]]. Consider the following equivalence relation on the nodes: <math>v\in V</math> and <math>w\in V</math> are equivalent if, and only if, there is a path fmo <math>v</math> to <math>w</math> and a path from <math>w</math> to <math>v</math> in <math>G</math>. The equivalence classes are called the '''strongly connected components (SCC)''' of <math>G</math>.
Let <math>G=(V,A)</math> be a [[Basic graph definitions|directed graph]]. Consider the following equivalence relation on the nodes: <math>v\in V</math> and <math>w\in V</math> are equivalent if, and only if, there is a path fmo <math>v</math> to <math>w</math> and a path from <math>w</math> to <math>v</math> in <math>G</math>. The equivalence classes are called the '''strongly connected components (SCC)''' of <math>G</math>.



Revision as of 19:47, 12 October 2014

Definition

Graph with marked strongly connected components

Let [math]\displaystyle{ G=(V,A) }[/math] be a directed graph. Consider the following equivalence relation on the nodes: [math]\displaystyle{ v\in V }[/math] and [math]\displaystyle{ w\in V }[/math] are equivalent if, and only if, there is a path fmo [math]\displaystyle{ v }[/math] to [math]\displaystyle{ w }[/math] and a path from [math]\displaystyle{ w }[/math] to [math]\displaystyle{ v }[/math] in [math]\displaystyle{ G }[/math]. The equivalence classes are called the strongly connected components (SCC) of [math]\displaystyle{ G }[/math].

Input

A directed graph [math]\displaystyle{ G=(V,A) }[/math].

Output

A set of sets of nodes. Each set of nodes contains exactly the nodes of one SCC. The correspndence between SCC and sets of nodes is one-to-one.