1788A - One and Two

Problem idea: azberjibiou

1788B - Sum of Two Numbers

Problem idea: azberjibiou

1788C - Matching Numbers

Problem idea: azberjibiou

1788D - Moving Dots

Problem idea: azberjibiou

1788E - Sum Over Zero

Problem idea: azberjibiou

Problem solver: YeongTree

1788F - XOR, Tree, and Queries

Problem idea: azberjibiou

Hello Codeforces and welcome back to another div2 round.

YeongTree and I are excited to invite everyone to participate in Codeforces Round 851 (Div. 2), which will be held on Feb/09/2023 17:35 (Moscow time).

This round is rated for the participants with ratings strictly lower than 2100. You will be given 6 problems and 2 hours to solve them. All the problems are authored and prepared by YeongTree and me.

We would like to thank

• Arpa for excellent coordination and help with prepration.
• Alexdat2000 for Russian translation.
• constructive, as_dfsdf, lumine_scence, nlog, Ryute, Konijntje, hanbyeol_, Physics07, jjang36524, octane, ahgus89, deltarune, KimDohoon, andyandy, PUFL, Pratyush1606, PUPA, Justice_Hui, garam1732, windva, culver0412, nor, maomao90, MagentaCobra, dorijanlendvaj, RetiredPlayer, mejiamejia, AquaMoon, mjhmjh1104, qwexd, ayhan37 for testing and feedbacks.
• MikeMirzayanov for great systems Codeforces and Polygon.

The score distributions will be updated later.

UPD1: Score distribution: $$$500−1000-1500-2250−2500-3000$$$

UPD2: Congratulations to the winners!

Overall:

1. jiangly
2. MakaPakka
3. Puranya
4. maspy
5. tute7627

Rated participants

1. MakaPakka
2. _10circle_
3. JJcjn
4. 1cm
5. AnotherYearWasted

AC submissions at the last second

• gsmdfaheem
• YoussefMorad1
• darshil_31

UPD3: Editorial is out