Greetings, fellow Perl Monks,

Please accept my sincere gratitude for being a wonderful Perl resource for everyone!

With great humility and respect, I put forth this question before you:

I am developing a new graph algorithm that utilizes the Graph module. The Graph module provides the $g->vertices() method. The results this method returns in a list context, are not deterministic. That is, for the same graph, when you call: 

my @vertices = $g->vertices();
the vertices might be in different order. Since I rely on this method, my algorithm is also not deterministic. For a fixed given input, my algorithm produces the correct result, but the number of times it recurses varies wildly.

I could just change it to: 

my @vertices = sort $g->vertices();
everywhere, but that would kill the performance of the algorithm. Is there a better way?

Also, I would appreciate any tips on computing the Big-O complexity of an algorithm implemented in Perl. Does one have to mentally unfurl every line of Perl down to C, while computing the complexity?

I await your wise and erudite responses to enlighten me.

In reply to Algorithm Complexity and Determinism of Graph Module by ownlifeful

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