Fucked in the ass. Once you submit you can't try the same problem. You should be punished!

will there be English editorial?

Hi Arpa, I can not understand, why is this approach called dsu on tree? This approach has a nice trick to reduce complexity by saving data about "big child". I can't see any special similarity with general dsu approach. In general dsu problems, we merge 2 subset into 1 set by linked list approach. But, in your tutorial there is no "merge" function. Am I missing something?

Also I see that, in your 600E's solution 14554536 you used merge functon. I can't understand, could you please explain that code?

Yes, that's clear now. But, I can't understand the 2nd equation. What is being computed there and how: dp[i][j] = dp[i][j] + dp[i][j-1]*j*(i+2*(j-1)) ?

I can't understand the editorial.How did you derive the 1st equation: dp[i][j] = dp[i][j] + dp[i-1][j]*i ?? why multiplied by 'i'? I don't find it correct for following case: 1 1 2, suppose we add '3'. Now the set of elements is {1,1,2,3), so i=2,j=1. Now, dp[2][1]= dp[2-1][1]*2 = 1*2 = 2 = wrong.
correct permutations are more: 3121,1321,1231,1213 ..

Can someone explain their solution of D? Thanks!

when merging, node.ANSWER=(right.MAX-left.MIN) I guess
Link: https://goo.gl/a7Hj3L

Thanks a lot man!

any mirror?

Can you find what's wrong in this idea:

if n is even output -1 else we print this:
1 2 3 ... n
n+1 n+2 n+3 ... 2n
2n+1 2n+2 .. .. 3n
.
.
n*(n-1)+1 .... n^2

Thanks! :)

Sorry, didn't get it. what's "5 degree freedom of area"? And how to expand and contract area? Please elaborate!

Deja vu

could you please elaborate a bit on div2-hard?

can someone explain div2 medium?

it is not what I asked

what is h[v] and depth[v] in div2D editorial?

but 1 isn't a multiple of 3

can anyone explain statement or sample cases of problem E?

I think, He said to explain the problem not solution.
I also didn't get it, if a={1,1} and k=1 how is the answer 2? anyone explain please

can anyone explain what " lifting " means in div2D editorial?

editorial please!

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how is this dp solution? could you give some hints?

can anyone explain D div2 a bit more with examples? its editorial is not clear for me.

Adding "http://www.topcoder.com" creates this message:

so, I added this: "https://www.topcoder.com" but didn't work!

how to solve E? it seems less harder than D(how to solve D by the way)

constraints?

can anyone please explain how to do with segment tree?

Thanks for pointing out the error. but is there any solution without segment tree?

without segment tree:

suppose, find[i] is the position of next different element. we'll precalculate find[]. Now, after update(p,x) if A_p = A_p + ₁ then find[p] = find[p+1], if A_p != A_p + ₁ then find[p] = p+1

Bonus on problem E:

solve the same problem for a Graph.

The format of the contest is similar to that of Codeforces and TopCoder

is there any similar challenge phase or hacking options like TC and CF?

Then changing the "test round" timing would be better. Now, it is intersecting with next CF round.

I have exam tomorrow, can't play now. It would be better if you could explain now :)

problem A

It can be shown that the answer is simply the 1-based indices of the one bits in the binary representation of n.

how to show that? please explain!

Thanks!

can you share your code please?

div2 problem statements were unnecessarily too large. And compared to previous rounds, problems were not interesting at all. Mere implementations :/

but, I don't understand how the find() function was working, could you explain please? ideone link

My O(N^2 logN) solution is too much slow. I used faster I/O methods, c++ and no energy saving modes. Can you please take a look? Is this actually more than O(N^2 logN)?

Problem C: I didn't understand this line:

"Now we will make an array endPos, where endPos[i] is true when t[i, i + cur_len - 1] = s[i - cur_len + 1, i]. We will update this array, adding symbols t[i], t[i + 1], t[i + 2] and so on."

what is cur_len? How to find cur_len? "adding symbols t[i], ... so on." where are we adding what? and how to use endpos to get the final answer?

Please someone clarify it in details!

I don't understand problem D, can anyone make it more clear? Does the problem just wants us to find the number of points all line segment covers? or, it needs to deal with area and square?

that's right, I was so stupid. Thanks for replying :)

Can you point out that mistake please?

For problem D, I used compression, but TLE on test #16, can anyone explain why?
Code

Why DemiGuo's rating did not change being in TOP 5?

How to solve Similar Strings?

Contest has just ended. How to solve F, G and J ?? I only solved A and E.

ok

Thanks :)

So, there is no specific formula for this problem (in terms of math not complexity)? And, considering fibonacci series, answer will be always between 1.618^n to 2^n-1, right?

Thanks to you both. It would be more helpful if anyone could help me on the updated version of the problem.

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