Hello, Codeforces!

I am very excited to invite you to our contest Codeforces Round 1054 (Div. 3), which starts on . You will be given 7 problems and 2 hours and 15 minutes to solve them.

The problems were authored by me and __rose and soullless to solve and alter them.

The round will be hosted by the rules of educational rounds (extended ICPC). Thus, all solutions will be judged on preliminary tests during the round, and after the round, there will be a 12-hour phase of open hacks. After the open hack phase, all accepted solutions will be rejudged on successful hacks. Also, note that there is no score distribution — rank will be determined by number of problems solved, followed by penalty; wrong submissions will incur the usual penalty of 10 minutes, following the rules of educational rounds.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:

• take part in at least five rated rounds (and solve at least one problem in each of them)

• do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

We would like to thank:

• Vladosiya and soullless for wonderful coordination.

• Wansur and abc864197532 for red testing.

• ImDMka, Aldk and Away_in_the_heavens for orange testing.

• Hagry for purple testing

• Dif1rent, APMAH, sahaun and thespace for blue testing.

• 1BR444H1M, Batyi-A-019-28, HorridBear, Romakolesn and kartikchauhan189 for cyan testing.

• Erbolat-R-019-28, Yozhik and Fadlallah for green testing.

• MikeMirzayanov and KAN for the great platforms.

• Vinton Cerf, and Robert Kahn for inventing the internet.

• Nagi for not giving up football.

• You for participating!

UPD : the editorial is out.

In last contest I finally achieved Master. It still feels a bit surreal to see the orange next to my name after so many contests and late nights.

This blog is inspired by reirugan blog. So I decided to write something similar — a list of things I still don’t know.

• Every single thing in this list except $$$ \downarrow $$$

• Li-Chao Segment Tree

• Segment Tree Beats

• RMQ in $$$ O(n)/O(1) $$$

• Wavelet tree

• Mergesort tree

Becoming Master doesn’t really require knowing super advanced or obscure algorithms. You just need to keep solving problems, learning from them, and being consistent.

(Like my Brother said: You become BoxMaster XD)

If you are experiencing slow compilation in macOS, it might be due to MacOS SIP(System Integrity Protection).
To resolve this, you can disable SIP.
To check the status of SIP on MacOS 11.0 or later:

1. Open terminal. 
2. Write csrutil status
3. System Integrity Protection status: disabled/enabled.

This blog is concise but could be very helpful for you.