Med0b1011's blog

By Med0b1011, history, 4 months ago, In English,
 
 
 
 
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By Med0b1011, history, 5 months ago, In English,

Time : https://www.timeanddate.com/worldclock/fixedtime.html?msg=SRM%20727&iso=20180111T0200&ah=2&am=0

Author is Errichto

Also check : http://codeforces.com/blog/entry/57011

Please do not upvote my SRM blogs. I don’t want my contribution sky rocketing for something I do not take credit for. I only aware you so you don’t miss SRM’s like I did when cgy4ever ( or in the past, Chrome) stopped posting them.

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By Med0b1011, history, 5 months ago, In English,
 
 
 
 
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By Med0b1011, history, 6 months ago, In English,
 
 
 
 
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By Med0b1011, history, 6 months ago, In English,

Starts in few hours.

Date and Time : https://www.timeanddate.com/worldclock/fixedtime.html?msg=Topcoder%20SRM%20724&iso=20171128T1600&ah=2&am=0

Redoing this blog as it appears people liked it last time. (If there is someone from TC that prefers to post these kind of blogs, I will happily delete this).

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By Med0b1011, history, 6 months ago, In English,

Hello recently I attempted this problem: http://codeforces.com/contest/341/problem/D

I understand editorial's solution, but I found in comments a very nice solution, that appears it can be generalized to query sums or higher dimensions. Here is it.

Spoiler

Link to code : http://codeforces.com/contest/341/submission/4391987

I could only get a vague idea, but not much into detail of what's going on especially the code. With this being a 4 years old comment, I don't think it's a good idea to ask the guy who posted, but can anyone please clarify in an easier way, or provide similar problems/blogs to it? Perhaps how to solve this problem if it was for sum queries instead of xor using this technique.

Thanks.

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By Med0b1011, history, 6 months ago, In English,

Topcoder SRM 723 starts tomorrow.

https://www.timeanddate.com/worldclock/fixedtime.html?msg=Topcoder%20SRM%20723&iso=20171118T1700&ah=2&am=0

I only created this blog because cgy4ever stopped doing them. I always disliked knowing about SRMs before they start by like 1-2 hours so thought I'd post about it a day in advance. ( If there is someone from TC that prefers to post these kind of blogs, I will happily delete this).

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By Med0b1011, history, 7 months ago, In English,

Hi CF!

I was recently solving this problem : http://www.spoj.com/problems/KOPC12B/

The problem statement is just one line, so no need to rephrase it.

Knowing the solution to the problem without weights, and printing consecutive values, I guessed the answer to be n*C(2n,n)/2 after some trial and error and was surprised it passed.

I tried to arrive at a combinatronics proof by trying to pose the problem as counting binary strings with certain properties, but didn't get somewhere noticeable, I also tried changing (C(n,k)^2) to C(n,k) * C(n,n — k).

Any help proving this? Thanks.

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By Med0b1011, history, 7 months ago, In English,

Hello!

I was recently solving this problem : http://poj.org/problem?id=1823

The problem basically says given an array of maximum size of 16000 where each element is one or zero, we need to perform the following two operations.

-Set range [L,R] to ones or zeros.

-Query maximum length of a subarray of ones

The problem can be indeed be solved by a segment tree, however using bitset we can do updates in O(N/32), and with N being 16000 that's just 500.

The problem is in querying the maximum length, I haven't reached any solution better than N operations, are there any ways to achieve something like N/32 ?

Please note, I already know the segment tree solution, I'm interested in bitset.

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By Med0b1011, history, 9 months ago, In English,

Anybody has a clue?

It's been down for a long time..Sad to see such OJ with very useful tasks disappearing.

Does any body know if I can find Timus tasks somewhere else at least for now?

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