Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Keith Thompson Newsgroups: comp.lang.c Subject: Re: Suggested method for returning a string from a C program? Date: Thu, 20 Mar 2025 12:14:49 -0700 Organization: None to speak of Lines: 31 Message-ID: <87zfhfsedy.fsf@nosuchdomain.example.com> References: <20250319123647.000035ed@yahoo.com> <86msdfoq3b.fsf@linuxsc.com> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Thu, 20 Mar 2025 20:14:49 +0100 (CET) Injection-Info: dont-email.me; posting-host="2f20008cbcfa55ae60494be276e0bfaa"; logging-data="4043012"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+Pn27buI61Kmvm7MlZjFjC" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:GsQDnVOc7DrkcK65QpxuzMUrisQ= sha1:Inbos/YKLzIzVHbdBPwwP0zt+DM= Bytes: 2365 Tim Rentsch writes: > Michael S writes: >> On Tue, 18 Mar 2025 21:38:55 -0400 >> DFS wrote: >>> I'm doing these algorithm problems at >>> https://cses.fi/problemset/list/ >>> >>> For instance: Weird Algorithm >>> https://cses.fi/problemset/task/1068 >> >> It is not an interesting programming exercise. But it looks to me as a >> challenging math exercise. I mean, how could we give a not too >> pessimistic estimate for upper bound of length of the sequence that >> starts at given n without running a full sequence? Or estimate for >> maximal value in the sequence? >> So far, I found no answers. > > You may console yourself with the knowledge that no one else > has either, even some of the most brilliant mathematicians > of the last hundred years. In fact it isn't even known that > all starting points eventually terminate; as far as what has > been proven goes, some starting points might just keep going > up forever. I think someone has mentioned that this is called the Collatz Conjecture. According to Wikipedia, it's been shown to hold for all positive integers up to 2.95e20 (which is just under 2**68). -- Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com void Void(void) { Void(); } /* The recursive call of the void */