Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ut-sally.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!godot!harvard!seismo!ut-sally!crandell From: crandell@ut-sally.UUCP (Jim Crandell) Newsgroups: net.lang Subject: Re: Re: Optimization technique wanted... Message-ID: <332@ut-sally.UUCP> Date: Wed, 28-Nov-84 04:30:57 EST Article-I.D.: ut-sally.332 Posted: Wed Nov 28 04:30:57 1984 Date-Received: Fri, 30-Nov-84 07:01:29 EST References: <438@ima.UUCP> <258@scc.UUCP> Organization: U. Texas CS Dept., Austin, Texas Lines: 21 > A jump is first considered to be a long jump. If its target appears before > the jump leaves the ring buffer, it collapses to a short jump. > > I am not a mathmatician, but I belive that this algorithm is order O(n). > > Any comments? Well, since you asked, yes. It is O(n). It's also imperfect. Since you effectively make only one pass over the jump list, you get only the first-order effects; i.e., you initially assume (correctly) that all jumps will be long, so as the hope of shortening each one wanes, you give up on it without allowing yourself to take advantage of the abbreviation of its postrange caused by the shortening of jumps whose destinations haven't appeared yet at the time of the decision. Funny thing about O(p(n)) algorithms for NP-complete problems. They usually don't work quite right. -- Jim Crandell, C. S. Dept., The University of Texas at Austin {ihnp4,seismo,ctvax}!ut-sally!crandell