Will a source-removal sort always return a maximal cycle?

Posted by Jason Baker on Stack Overflow See other posts from Stack Overflow or by Jason Baker
Published on 2010-04-02T17:58:05Z Indexed on 2010/04/02 18:03 UTC
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Filed under:

graph-theory

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topological-sort

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dependencies

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source-removal

I wrote a source-removal algorithm to sort some dependencies between tables in our database, and it turns out we have a cycle. For simplicity, let's say we have tables A, B, C, and D. The edges are like this:

(A, B)
(B, A)
(B, C)
(C, D)
(D, A)

As you can see, there are two cycles here. One is between A and B and another is between all four of them. Will this type of sort always choke on the largest cycle? Or is that not necessarily the case?

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