It was so interesting)

What's the difference between these 2 codes on 3rd problem?

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define sz(v)  (int)(v).size()
#define all(v) (v).begin(), (v).end()

vector<int> pr, mn, mx;

int fnd(int x) {
	return pr[x] = (x == pr[x] ? x : fnd(pr[x]));
}

void uni(int x, int y) {
	x = fnd(x); y = fnd(y);

	if (x == y) return;

	pr[x] = y;
	mn[y] = min(mn[y], mn[x]);
	mx[y] = max(mx[y], mx[x]);
}

int main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);

	int n, Q;
	cin >> n >> Q;

	pr.assign(n, 0);
	iota(all(pr), 0);
	mn = mx = pr;

	while (Q--) {
		int tp;
		cin >> tp;

		if (tp == 1) {
			int x;
			cin >> x; x--;

			cout << mn[fnd(x)] + 1 << ' ' << mx[pr[x]] + 1 << '\n';
		}
		else {
			int l, r, len;
			cin >> l >> r >> len; l--; r--;
		
			for (int i = 0; i < len; i++) {
				uni(l + i, r + i);
			}
		}
	}
}

I think both of them should only get 45 pts.

Congrats! I realized I've been Expert for ~2.5 years 🙃

No comment. ( Though, I commented :) )

Could you please remove the gif?

Problems A-D1 are good, I think; I could've solved C2 if I had ~5 more minutes. Didn't have time to read E and its solve count is low.

Because of [trusted participants only]

Could you do again?

I think 455D - Серега и веселье solvable with that.

It's already available, link, but it's a bit wrong. System might've chosen it because of the problem is from Div2 with Div1 contest and I solved D1 in Div2 but didn't attempt in Div1 as B1.

The site chose 1967B1 - Reverse Card (Easy Version) but I had already solved it as 1972D1 - Reverse Card (Easy Version).

Yep.

You have to remove some/none of the elements then apply operations on resulting array.

I liked the contest, (luckily) there wasn't much diff for me between $$$D1$$$ & $$$D2$$$.
What is the chance of getting $$$+3$$$ or more after rating roll back?

Then, isn't the time complexity $$$O(NlogN + M^2log(\frac{N}{M}))$$$? And it's ~$$$2.6 × 10^8$$$(TLE?), but I don't now if we have to include $$$NlogN$$$, if don't it won't be TLE. Or is it $$$O(Nlog(\frac{N}{M}) + M^2log(\frac{N}{M}))$$$, if so it won't be TLE(?).

How did you calculate time complexity? I think my solution is same with yours, they have close time, but I can't find what time copmlexity of my solution is. 285897223

Not VPN, TOR browser with bridge.

Problem can be simplified like these: Let's call pair $$$(i, j)$$$ bad if $$$i \lt j$$$ and $$$a_i \gt a_j$$$. We need to find if maximum sum of bad pars, which is inside $$$[l_i, r_i]$$$, is not greater than $$$k$$$ (for all bad $$$(i, j)$$$ satisfies $$$a_i + a_j \le k$$$).

Create a segment tree for maximum value and a merge sort tree where each node has a sorted vector containing all elements in the range of this node. Store the maximum sum of bad pair, which is inside $$$[l_{node},r_{node}]$$$, in $$$vis_{node}$$$. Now we can answer the query recursively like a segment tree. For some $$$node$$$ if $$$[l_{node},r_{node}]$$$ is outside $$$[l_i, r_i]$$$ its answer is $$$true$$$. If its entirely contained, first we check if $$$vis_{node} \le k$$$, if so we can do binary search on the vector to find the greatest element which is smaller than $$$mx$$$ (max number before this segment($$$node$$$)) to find maximum sum of bad pairs which right element is in $$$[l_{node},r_{node}]$$$ and left element is in $$$[l_i, l_{node} - 1]$$$. And check $$$mx + element \le k$$$ then update $$$mx$$$. If neither of the previous conditions are satisfied, we take the answer of the left child and the answer of the right child. Check if they are both $$$true$$$. Time complexity for building the merge sort tree is $$$O(nlogn)$$$ because we go through each element $$$logn$$$ times, and the time complexity for answering the queries is $$$O(qlog^2n)$$$ because in each query we visit logn nodes at most, doing binary search in each one in $$$O(logn)$$$.

Could you please predict mine?

Thx!

In problem B you must take numbers such that have distinct parities. So you can remove even + even & odd + odd options from editorial. EDIT: I'm a bit late to tell it first.

Where did you get them?

Is there any way to know what would their CF rating be?

Thanks for clarification.

Can you make it work on CF mirror too?

Wasn't it supposed to be CodeTon Round 9?

This will be my birthday contest :)

Nice D but not C(I don't know how my code for C is true).

Thanks!

It'd be good if you continue the streak of announcements with photos of the authors :)

Thanks, I didn't know it.

Thanks.

It's nice but I hate reading. What about using whole graph?

What about mine?(after CF 920 rating change)

Hope to have fun in $$$1^{st}$$$ contest of $$$2024$$$.

The moon is beatiful, isn't it? But this contest is ...

stdfloat kompo

What's the difficulty of the problems in silver/gold? What would their rating be in CF? Are the difficulties of the problems the same every month or do they get harder every month?

Yeah, I made it.

In bronze, I solved full A, 1-6 of B, full C. Is my point 333 + 138 + 333 = 804? Will I pass bronze to silver?

Can someone tell me what is 8 Kyu in my atcoder profile? I'm new on atcoder.

Just like mine.

Why there's no 1,024-2047 places: 1 TON each?

No, it's not avaiable.

I don't have smartphone and freebrowser doesn't support pc.

Chinese round at usual time. It's unusual, isn't it?

I also want to know.

I'm going to try all of this

It's time to rage(100%)

Unfortunately I can't access it.

Thanks for your comment. Could you answer other questions too?

It's blocked too.

Forunately, Tor connects with bridges.

First time to solve till F, my best performance in div3 :)

I'm using TOR in Ubuntu 23.04. I shared it to my friends but it didn't work for all of them, only works on me. Will I be able to use TOR after installing Ubuntu 23.10 to my pc? I want to install but I'm a bit worried about TOR. I also sent this to [email protected].

All of them blocked, but I can access with TOR.

Exciting, it'll be hard to wait 3 days, hope to get at least +5. GL & HF

Cat, it was just a joke.

I wouldn't if it wasn't solved by so many people.

I couldn't solve C, should I commit suicide?

They aren't blocked in Turkmenistan(written on your profile):
1. CPH : https://usaco.guide/CPH.pdf
2. CP4-1 : https://isi-junior.com/klass/cp4-1.pdf
3. CP4-2 : https://isi-junior.com/klass/cp4-2.pdf

Which school do you study? I'm also Yhlas 2008, Ashgabat TKM.

I also want to know.

Doesn't work, but I can use Tor.

OK, thx.

After some hard works, I finaly managed to install Tor. It doesn't connect directly but it connects with bridges. :)

Tor and I2P's websites are blocked, and I couldn't install its snap(an error occurs).

Proton VPN didn't work for me. :(

I tried but didin't work. :(

Blocked. :(

But atcoder is blocked here. :(

Thx!!!

It passed system testing too, but how???

Can someone explain why my code isn't TLE for 1870D - Prefix Purchase?

Blocked. :(

Why there's no 1,024-2047 places: 1 TON each?

What am I missing?

Alright so I've solving *1600 diff. problems, when I try to solve *2100 diff. problems on codeforces I get stuck and can't come up with solutions nor understand the solutions well often time. What should I do? Any help would be appreciated!

What is Shaazzz? What does it have?

My worst div.3, I solved only A-D(lately, beacuse of C) in contest, upsolved F. For me: C>D, E>F. But I couldn't solve F in contest. Hope better next time.

Yes, I use usaco, it's not blocked but I want to try other OI problems too. I also use usaco training. I'm in section 5.3.

idk, for example what?

It's blocked

Site is blocked and I use Ubuntu.

In blog : The problems were invented and prepared by ..., Roman Roms Glazov, ...
But in contests page Roms doesn't exist.

As a blue participant, I hope to stay blue after this round. GL & HF

Thx!!!

I become Expert)))

Nice contest, thx!!!

Thanks for the round. I solved until problem E. Problems up to E were fine for me, except for problem B.

Me too!!! GL & HF to all <3

It's blocked too. :(

You accept that you created acc just for writing comment.

Why don't you set a regular CF round?
Will come in the next few months :)

Passed 1.5 month. When will?

Did you creat new account just for saying your feelings about his username?