http://www.tomfotherby.com/blog/index.php/2007/08/finding-the-median-in-linear-time/ My little place in cyberspace Tue, 10 Jan 2012 23:59:26 +0000 hourly 1 http://wordpress.org/?v=3.3 http://www.tomfotherby.com/blog/index.php/2007/08/finding-the-median-in-linear-time/comment-page-1/#comment-8907 Vladimir Sat, 18 Dec 2010 15:55:48 +0000 http://www.tomfotherby.com/blog/index.php/2007/08/finding-the-median-in-linear-time/#comment-8907 These algorithms do not run in linear time. First of all, int a = *A.begin(); -- is a bad choice: for a sorted array this algorithm will find median in quadratic(!) time. int a = A[random()%A.size()]; -- a bit better, but worst case is still quadratic, though expected time is linear. See wikipedia for better (and more complex) choices. These algorithms do not run in linear time.
First of all,
int a = *A.begin();
– is a bad choice: for a sorted array this algorithm will find median in quadratic(!) time.
int a = A[random()%A.size()];
– a bit better, but worst case is still quadratic, though expected time is linear.
See wikipedia for better (and more complex) choices.

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