The algorithm is fair, but it's not an implementation of the Fisher-Yates shuffle. In fact, the solution has a pretty poor assymptotic running time: Ω (n²). This is due to the splicing of the array. Splicing out a single element of an array takes, on average, time linear to the length of the array. The algorithm presented by the OP splices out elements of successively smaller arrays, but it still adds up to quadratic time.

I've been pushing the Fisher-Yates shuffle instead of the splicing shuffle since 1995 or so. Since then, it has made its way into the FAQ, we have List::Util::shuffle, but despite the FAQ spelling out what's wrong with the splicing algorithm, that one just doesn't want to die.

Abigail

In reply to Re: Is this a fair shuffle? by Abigail-II
in thread Is this a fair shuffle? by saintmike

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