Search found 17 matches

by Cubist
Mon Jun 24, 2002 4:03 am
Forum: Volume 1 (100-199)
Topic: 138 - Street Numbers
Replies: 93
Views: 7114

For solving this problem is best to learn a tiny bit of math. Here's a good reference: http://www-gap.dcs.st-and.ac.uk/~history/HistTopics/Pell.html Basically, if you're trying to solve an equation like m^2 - d*n^2 = 1 where d is squarefree, all you need to do is find an initial (smallest) solution ...
by Cubist
Sat Jun 22, 2002 10:59 am
Forum: Other words
Topic: Forum for CIII
Replies: 8
Views: 3387

I sent a message to the moderator of these forums; is there anyone else
to contact about adding VIII and CIII?
by Cubist
Fri Jun 21, 2002 9:42 am
Forum: Volume 4 (400-499)
Topic: 436 - Arbitrage (II)
Replies: 17
Views: 5219

436: Arbitrage

Did anyone try to solve this using a numerical eigenvalue method? I think I'll try it, just for fun. Arbitrage is possible iff the largest eigenvalue is greater than 1, and is equal to limit of the best arbitrage sequence of length n, raised the the 1/n power, limit as n -> infinity. This will give ...
by Cubist
Fri Jun 21, 2002 9:34 am
Forum: Volume 8 (800-899)
Topic: 847 - A Multiplication Game
Replies: 41
Views: 20114

Consider the related game (e.g. taking the log of the numbers in this problem) of A and B choosing real numbers in the interval [a,b]. Regardless of what the first player chooses, the 2nd player can force the sum of the two numbers chosen to be a+b. Thus, if the 2nd player (B) wins the game with sum...
by Cubist
Fri Jun 21, 2002 7:21 am
Forum: Other words
Topic: Forum for CIII
Replies: 8
Views: 3387

Yes, please do! Forums for 8xx and 103xx ... ! :roll:
by Cubist
Mon Jun 17, 2002 7:10 am
Forum: Other words
Topic: Problems accessing Online Judge status
Replies: 6
Views: 2411

Does anyone know what's wrong with the online judge status, and
when it will be working again? I'm anxious to see the current
statistics. :cry:
by Cubist
Thu Jun 13, 2002 3:12 am
Forum: Other words
Topic: Submitting new problems?
Replies: 1
Views: 1484

Submitting new problems?

I have a couple of problems which would be excellent to use on Valladolid. Is there any way to submit problem proposals? I could submit quality test data for them, as well. I didn't see any reference to submitting new problems anywhere. -- Chris Long, Departments of Mathematics & Statistics, Rutgers...
by Cubist
Wed Jun 12, 2002 11:20 pm
Forum: Volume 100 (10000-10099)
Topic: 10025 - The ? 1 ? 2 ? ... ? n = k problem
Replies: 42
Views: 11794

Doh!

Many apologies - I'm new here, and hadn't realized the multiple input condition at all! It'd be nice if this was mentioned in the problems themselves, e.g. Note: multiple input (with link to the page describing the multiple input condition). It's certainly a small thing, but it would save people fro...
by Cubist
Wed Jun 12, 2002 7:30 pm
Forum: Volume 100 (10000-10099)
Topic: 10025 - The ? 1 ? 2 ? ... ? n = k problem
Replies: 42
Views: 11794

10025 - The ? 1 ? 2 ? ... ? n = k problem

The problem description doesn't say that the first input is the number
of items to process! Please fix this!

-Chris
by Cubist
Wed Jun 12, 2002 8:57 am
Forum: Volume 102 (10200-10299)
Topic: 10207 - The Unreal Tournament
Replies: 23
Views: 6371

Doh!

Doh! Look at the last few lines (special cases). Everything else was correct; I was accepted after formatting the special cases correctly. :D I got the 2nd fastest running time, and the lowest memory usage. I found a nice closed form for the number of recursive calls, which is why it ran quickly. No...
by Cubist
Wed Jun 12, 2002 4:59 am
Forum: Volume 102 (10200-10299)
Topic: 10207 - The Unreal Tournament
Replies: 23
Views: 6371

Can anyone check these values?

I get wrong answer, but I don't see the problem. Can anyone check these values? INPUT: 0.5 3 100 100 7 3 3 8 0.7 3 500 500 11 7 2 11 0.5 3 0 1 1 0 0 0 0.7 0 OUTPUT: 0.50000 181097029312206562330808354154968327749009179350826673682638 0.08984 238 0.94531 328 1.00000 5405764818908731390312293872519505...
by Cubist
Tue Jun 11, 2002 11:09 am
Forum: Pascal
Topic: GMP Unit
Replies: 0
Views: 2098

GMP Unit

Can we use the GMP unit? I'm wondering because problem 10207
requires handling up to perhaps 500 digit numbers. The problem is
mathematically simple, handling the large numbers is the problem here.

-Chris
by Cubist
Mon Jun 10, 2002 3:58 am
Forum: Volume 101 (10100-10199)
Topic: 10110 - Light, more light
Replies: 76
Views: 26121

10110 - Lights, more lights (slow and fat)

How do you reduce either the running time or the memory usage for this problem? I was astonished to see my tiny Pascal program using 0.670 seconds and something like 468K! This code doesn't use anything that other programs I'm submitted, which all ran in 0.000 and 64K. Any ideas? -- Chris Long, Math...
by Cubist
Sun Jun 09, 2002 5:28 am
Forum: Volume 1 (100-199)
Topic: 138 - Street Numbers
Replies: 93
Views: 7114

Related Math

See the topics "quadratic forms" and "continued fractions". The key is
finding base solutions; from those you have a nice recursion that
generates others.
--
Chris Long, Mathematics Department, Rutgers University

It is pitch black. You are likely to be eaten by a grue.
by Cubist
Sat Jun 08, 2002 1:25 am
Forum: C
Topic: Allowed/restricted C functions
Replies: 2
Views: 3316

Allowed/restricted C functions

Is there a list somewhere of allowed/restricted C functions for Valladolid? I seem to recall one somewhere, but I can't find it now. I seem to recall that it listed allowed/restricted Pascal and Unix functions, as well. -- Chris Long, Mathematics Department, Rutgers University The beatings will cont...

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