> So if I wanted to look like a c/c++ god, I'd
> have things like K&R and Stroustroup, and NOT
> some "dummies guide", even if I don't know how
> to properly format a 'for' statement.
As a small side note I warmly recommend K&R over any dummies book even if you can't format a 'for' statement. It's the C book for everyone really:)
Actually you got it backwards, Multics was extremely multiuser, was the reasoning behind the name. UNIX started out as largely a singleuser simplification of Multics (which was a very complex system), first named UNICS, which makes the pun much simpler to understand. The name was changed to UNIX when multiuser support was added.
Multics is really to operating systems what Algol was to programming languages, the huge research project where they found a lot of the do's and dont's in operating system design. A great system all in all, a bit too ahead of its time though.
See http://www.wagoneers.com/UNIX/City-U/Multics/ for more information.
No, took an hour to both implement it and then run it for long enough to notice that it wasnt likely to finish anytime soon. As it happens I have since slept and discovered that the code is somewhat moronic too but that's what you get for trying to code in the middle of the night, crappy code to solve an unsolvable problem:)
Also could be noted that I implemented it in Matlab at first, but noticed that it ran off the range of a 64 bit integer quickly, so I reimplemented it (badly) in C with GMP to support arbritrarily sized numbers and get some speed out of it (at this point I still thought 691 was just hard, not that hard:), seeing I had never used GMP before it involved a bit of manual reading and such.
And just to note, one should not use GMP for this problem, was too sleepy to see that yesterday though, better off maintaining and array of actual base 10 digits and doing the adds "by hand".
I hate you.
I spent an hour writing a program to calculate these damn numbers and crunching on 691 before I got the joke:P
Oh well, I learnt a bit of GMP in the process, guess it was not all wasted.
Slashdot Mirror
"Practice in mathematics is using mathematics to invent new mathematics, it is not in any fucking way related to bridges."
Translated from swedish, hopefully decently true to the original swedish quote :)
> So if I wanted to look like a c/c++ god, I'd > have things like K&R and Stroustroup, and NOT > some "dummies guide", even if I don't know how > to properly format a 'for' statement. As a small side note I warmly recommend K&R over any dummies book even if you can't format a 'for' statement. It's the C book for everyone really :)
Actually you got it backwards, Multics was extremely multiuser, was the reasoning behind the name. UNIX started out as largely a singleuser simplification of Multics (which was a very complex system), first named UNICS, which makes the pun much simpler to understand. The name was changed to UNIX when multiuser support was added.
Multics is really to operating systems what Algol was to programming languages, the huge research project where they found a lot of the do's and dont's in operating system design. A great system all in all, a bit too ahead of its time though.
See http://www.wagoneers.com/UNIX/City-U/Multics/ for more information.
Also could be noted that I implemented it in Matlab at first, but noticed that it ran off the range of a 64 bit integer quickly, so I reimplemented it (badly) in C with GMP to support arbritrarily sized numbers and get some speed out of it (at this point I still thought 691 was just hard, not that hard :), seeing I had never used GMP before it involved a bit of manual reading and such.
And just to note, one should not use GMP for this problem, was too sleepy to see that yesterday though, better off maintaining and array of actual base 10 digits and doing the adds "by hand".
Requires GMP, build it with something along the lines of
gcc -o lychrel -O2 -lgmp lychrel.c
and run with a number as argument to try it for the lychrel property. Makefiles are for wimps ;)
I hate you. I spent an hour writing a program to calculate these damn numbers and crunching on 691 before I got the joke :P
Oh well, I learnt a bit of GMP in the process, guess it was not all wasted.