Search found 39 matches

by Aleksandrs Saveljevs
Sat Mar 05, 2005 3:48 pm
Forum: C++
Topic: vector->at(i) ?
Replies: 4
Views: 2689

You can do it like this: "(*p)[1]". For example,

Code: Select all

vector<int>* p;
p=new vector<int>();
p->push_back(4);
p->push_back(8);
printf("%d\n", (*p)[1]);
delete p;
by Aleksandrs Saveljevs
Wed May 12, 2004 6:06 pm
Forum: Algorithms
Topic: Optimisation
Replies: 5
Views: 1641

Hello. Hmmm, I'm not entirely sure about this. Looking up a table involves pointer arithmetics, so I don't think you gain anything by exchanging an integer subtraction with a pointer addition... You know, I thought about this too, but I remember that it gave me a little boost on one of the problems....
by Aleksandrs Saveljevs
Tue May 11, 2004 9:59 pm
Forum: Algorithms
Topic: Optimisation
Replies: 5
Views: 1641

I did this pervert code writing for a while... :) In "string-int" there is a faster way (performing less arithmetic operations using a look-up table). In "int-string" you can speed this up considerably. Let me give you a hint: get rid of two divisions (very expensive operation) and reverse(buffer). ...
by Aleksandrs Saveljevs
Wed May 05, 2004 10:22 pm
Forum: Volume 106 (10600-10699)
Topic: 10650 - Determinate Prime
Replies: 67
Views: 23920

mavy wrote:I found 156 sequences from 1 to 32000, is this correct ?
No.
sohel wrote:And I got 162 different determinate sequence for 0 32000. Is this correct?
Yes. :)
by Aleksandrs Saveljevs
Mon Apr 19, 2004 7:56 pm
Forum: Volume 4 (400-499)
Topic: 484 - The Department of Redundancy Department
Replies: 103
Views: 7979

WR, hi.
Sorry for leaving you waiting for so long. :oops:

Your code looks good to me. I still suggest reading in a char-by-char way. I think you should try it if it helped Bernardo. (Bernardo, did it?)

PS: Hey, you don't dispose anything!.. :wink:
by Aleksandrs Saveljevs
Sun Apr 18, 2004 8:48 pm
Forum: Volume 106 (10600-10699)
Topic: 10634 - Say NO to Memorization
Replies: 18
Views: 8277

By the way, make sure you don't use the advantage of the fact that

Code: Select all

c(n, k) = c(n, k-1) * (n-k+1) / k
There will be trouble with the overflow. :wink:
by Aleksandrs Saveljevs
Sat Apr 03, 2004 11:54 am
Forum: Volume 1 (100-199)
Topic: 100 - The 3n + 1 problem
Replies: 1394
Views: 172940

Justin, hi.
Justin wrote:If the program is wanting more than 4 inputs or there is some strict strict procedure that you aren't telling people who're new to this system, i'd like to know.
You should read until end-of-file. That's all. Good luck! :)
by Aleksandrs Saveljevs
Sat Mar 27, 2004 10:49 pm
Forum: Volume 4 (400-499)
Topic: 484 - The Department of Redundancy Department
Replies: 103
Views: 7979

Bernardo, hi. 1) I suggested reading in a char-by-char way, because there might be some spaces or blank lines in the end after the last number and Pascal might not detect the end of input properly. 2) The whole input file is one big sequence of numbers. You should not stop when end-of-line is reache...
by Aleksandrs Saveljevs
Sat Mar 27, 2004 7:23 pm
Forum: Volume 4 (400-499)
Topic: 484 - The Department of Redundancy Department
Replies: 103
Views: 7979

I have this one solved in Pascal a long time ago. Longint is OK and the array size is around 100,000. The only thing I can suggest: try reading in a char by char way. Or rewrite it in C/C++. :)
by Aleksandrs Saveljevs
Sat Mar 27, 2004 3:25 pm
Forum: Algorithms
Topic: help with one "usaco hard problem" ... please.....
Replies: 19
Views: 9437

Hello.
The post is 3 months old... are you still stuck with it? I believe I could give you some hints on this one. :)
by Aleksandrs Saveljevs
Thu Mar 25, 2004 12:34 am
Forum: Other words
Topic: Problems from past World Finals
Replies: 3
Views: 3005

Take a look here: http://acmicpc-live-archive.uva.es.

Happy solving! :)
by Aleksandrs Saveljevs
Mon Mar 22, 2004 3:01 pm
Forum: Volume 4 (400-499)
Topic: 437 - The Tower of Babylon
Replies: 14
Views: 7808

Joan, hi. This is my output: Case 1: maximum height = 342 Case 2: maximum height = 588 Case 3: maximum height = 5 Case 4: maximum height = 481 Case 5: maximum height = 180 Case 6: maximum height = 273 Case 7: maximum height = 200 Case 8: maximum height = 310 Case 9: maximum height = 50 Hope that hel...
by Aleksandrs Saveljevs
Mon Mar 22, 2004 12:54 am
Forum: Volume 7 (700-799)
Topic: 750 - 8 Queens Chess Problem
Replies: 78
Views: 25706

There's a blue tick next to the problem's name on this page. It means multiple input. I'll copy-paste the meanings of the colours: The yellow colour means a special correction program for that problem; the blue colour means multiple input; finally, the green colour (a mix of blue and yellow) means a...
by Aleksandrs Saveljevs
Sun Mar 21, 2004 11:54 pm
Forum: Volume 7 (700-799)
Topic: 750 - 8 Queens Chess Problem
Replies: 78
Views: 25706

Well, it's a multiple input problem... :wink: Probably, 20 is the number of test cases.

PS: For the description of multiple input format take a look here.

Good luck! :)
by Aleksandrs Saveljevs
Sat Mar 06, 2004 9:25 pm
Forum: Volume 8 (800-899)
Topic: 825 - Walking on the Safe Side
Replies: 38
Views: 19952

Dima, hi. I think I have an answer to your not a very recent question. :) Is it nessesary to use long arithmetic? Nope. Can somebody post a few inputs and outputs? Here you are: 8 1 1 1 1 8 1 1 8 1 4 8 1 1 2 3 4 5 6 7 8 8 1 1 2 3 4 1 5 6 7 8 4 4 1 2 3 4 8 8 1 2 3 5 4 1 4 5 3 6 6 2 7 7 8 8 8 8 1 2 6 ...

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