## Search found 284 matches

Sat Jul 13, 2002 11:05 am
Forum: Volume 1 (100-199)
Topic: 139 - Telephone Tangles
Replies: 66
Views: 8369
Can you handle names that have spaces, like "Los Angeles"?
Fri Jul 12, 2002 7:36 pm
Forum: Other words
Topic: Thanks Everybody
Replies: 7
Views: 2922
It's also important to think the way Judge can solve this problem. Yeah right. Since when can I look into your head?!? So there is no problem with input output. 1 out of 84 submissions was accepted. And the person who got it needed three attempts. I consider this a major problem. Don't you think yo...
Thu Jul 11, 2002 5:33 pm
Forum: C
Topic: about output of floating point numbers
Replies: 7
Views: 3644
80 bits are about 24 decimal digits. Your number has 66. I'm not surprised at all that you lose precision. I'm not sure if the modulo operator works on doubles&Co. There's the function double fmod(double x, double y); but maybe they just added it for other reasons. Really don't know... You can get P...
Wed Jul 10, 2002 11:01 am
Forum: Volume 103 (10300-10399)
Topic: 10303 - How Many Trees?
Replies: 19
Views: 3184
I think you should really start with the formula mentioned in CLRS. Here it is:

c(n) = 1/(n+1) * (2n choose n)

Then rewrite the "choose" part with something more useful and try it like this:

c(n+1) = ... = and-here-something-that-includes-c(n)-and-not-much-more.
Sun Jun 30, 2002 7:39 am
Forum: Other words
Topic: Graph problems
Replies: 5
Views: 1926
Hmm, I might be wrong, but I think what you mean with the brute force method might be more appropriately be called backtracking. When I think DFS, then I see the O(V+E) algorithm that traverses every part of the graph exactly once, without taking back choices made (i.e. the DFS tree is only extended...
Sat Jun 29, 2002 9:25 pm
Forum: Other words
Topic: Graph problems
Replies: 5
Views: 1926
You couldn't be more wrong. DFS rules, it's one of the fastest and most versatile algorithms out there and because of that one of my favourite algorithms. In particular for the detection of cycles, please name another algorithm that solves it faster or is easier to code. I think I can't name one.
Wed Jun 26, 2002 8:38 am
Forum: Volume 1 (100-199)
Topic: 100 - The 3n + 1 problem
Replies: 1394
Views: 185133
maybe "while( current <= j )" will work?
Wed Jun 26, 2002 8:36 am
Forum: Volume 1 (100-199)
Topic: 108 - Maximum Sum
Replies: 233
Views: 23181
Could you please use the bbtags to format the code?
Mon Jun 24, 2002 11:27 pm
Forum: Volume 6 (600-699)
Topic: 681 - Convex Hull Finding
Replies: 60
Views: 20678
Somebody wrote the hint that n can be much larger than 512. Maybe that's it?
Mon Jun 24, 2002 10:05 pm
Forum: Volume 8 (800-899)
Topic: 835 - Square of Primes
Replies: 22
Views: 11549
So how long would your non-precalced version run on the judge? Btw, please mark precalc solutions with a "precalc" comment, so that others don't waste time to search for the superior algorithm that doesn't exist. Well, I have to admit that I've just made up this rule for me ;-) (never thought about ...
Mon Jun 24, 2002 9:15 am
Forum: Volume 103 (10300-10399)
Topic: 10303 - How Many Trees?
Replies: 19
Views: 3184
Yep, just solved it. Starting with the formula of CLRS, you can get an easy recurrence relation of the form c[0] = 1 c[n+1] = f( n, c[n] ) where f is really a simple function. Let's ignore that working with large numbers takes more time than with simple ints, i.e. let's assume the arithmetic operati...
Mon Jun 24, 2002 7:12 am
Forum: Volume 4 (400-499)
Topic: 402 - M*A*S*H
Replies: 56
Views: 13587
mido: yes

10153EN: "left" as in "left out" and "right?" like in "am I right?"
Mon Jun 24, 2002 3:05 am
Forum: Volume 8 (800-899)
Topic: 835 - Square of Primes
Replies: 22
Views: 11549
Ha! Not anymore! I took the lead again Unfortunately my program became bigger and uglier now. But beware: I could easily make it even bigger and uglier, and it would probably be even faster, too, harhar
Sun Jun 23, 2002 11:44 pm
Forum: Volume 1 (100-199)
Topic: 138 - Street Numbers
Replies: 93
Views: 7235
Ok, I see... you're right, the sums are of course out of int-range. What you could do is use "long long" or "double", both should work. Don't use "long", because that's usually the same as "int", even though they have different names.
Sun Jun 23, 2002 7:15 am
Forum: Volume 8 (800-899)
Topic: 835 - Square of Primes
Replies: 22
Views: 11549

### Re: Mail me if you want hints

I must confess my first approach was similar to yours, using the notion of prefix, and I needed some hints (this program has been studied by some people) to make an accpetable solution. Hmm, that sounds like if there's some mathematical insight behind it... My solution is just a brute force one, bu...