ref: a605a17d05acf4d981219c5e8db3def0b67a5c4a
parent: 6bce285027a9eacd50b92b5a26e1cd3c5c69a4ca
author: Simon Tatham <anakin@pobox.com>
date: Fri Jul 22 07:06:57 EDT 2005
James H profiled the new Same Game grid generator and discovered it was spending 60% of its time in shuffle(). The purpose of the shuffle() call was to go through a largish array in random order until we found an element that worked, so there's no actual need to shuffle the whole array every time and I only did it out of laziness. So I now pick a random element each time I go round the loop, meaning I save a lot of shuffling effort whenever the loop terminates early (which is often). I get about a factor of two speed improvement from this small change. [originally from svn r6125]