On May, 5, 16:05 (UTC) Codeforces Round 350 is going to start! Yes, pay attention to the non-standard start time.
I took advantage of my official position and the round is expected to be a bit experimental with an expanded set of problems. Perhaps for experienced participants (sorry, Div 1) it could seem easy. This time, emphasis was placed on the main target audience of the round: so in the round will be a lot of very simple problems, but even the top of the second division will find something interesting. In addition, one of the problems will be offered in two versions — in a simplified version with small constraints and in a harder version with greater constraints. Thus, if you immediately realize solution for large constraints, you can write and submit the same code on the both version.
The problem writers are me and fcspartakm. We hope that you will enjoy the problems and the round will be fun and useful!
The expected scoring is:
- A: 500
- B: 750
- C: 1000
- D1: 1000
- D2: 500 (i.e. the complete solution of D is 1500 points)
- E: 2000
- F: 2500
UPD: As it was pointed in the comments we have a tricky point about hacks with problems D1/D2.
To avoid the situation when participant locks the problem D1 and looks the solution of the problem D2 in his room, you are allowed to lock the problems D1/D2 only together in the same time and only if both of your solutions for this problems passed the pretests. In the other words, the possibility to lock D1/D2 will appears only after you solved both problems. The problems D1/D2 will be locked together in the same moment.
To avoid the situation of double reward for hack of D1 and D2 of the same participant, the participant A after successful hack of the participant B on the problem D1 loses the possibility of the hack B on the problem D2. Similarly if the participant A successfully hacks the participant B on the problem D2, then A loses the possibility of the hack B on D1.
UPD 2: The round is over. My congratulations to the winners! Here are the heroes of the round.
The Top-5 among the official participants:
The Top-5 among the unofficial participants:
UPD 3: Problem analysis is now available.