Hi Codeforces! I am proud to invite you to the online mirror of 2022 Taiwan NHSPC Mock Contest!

The National High School Programming Contest (NHSPC) is an official informatics contest from Taiwan, where the top ten students enter the spring training camp, in which the IOI participants are selected. The NHSPC Mock Contest is a contest prepared by former OI participants from Taiwan, and helps contestants prepare for the official NHSPC which takes place the following week. This year, we have decided to hold an online mirror on Codeforces, so people around the world can participate.

The mirror on Codeforces takes place on Saturday, December 10, 2022, 9 AM UTC+8, and will last for 5 hours until Saturday, December 10, 2022, 2 PM UTC+8. The scoring is in IOI format, there will be 7-9 problems, each of which has a maximum score of 100 points. There will be subtasks of varying difficulty in each problem, and we hope that the problems will be interesting for contestants at all rating levels. The problem statements will be in English and (Traditional) Chinese.

UPD: Registration has begun! You can register on the Codeforces Gym.

I would like to thank our team of problem setters and testers for making this contest possible: abc864197532, BurnedChicken, doublewang, baluteshih, FHVirus, hhhhhaura, WiwiHo, syl123456, yungyao, Fysty, amano_hina, ToxicPie9, Your_Name, SorahISA, HNO2, daniel071292, joylintp. Special thanks to Wayne_Yan for helping with problem statements and translation.

As a problem setter, I strongly recommend this contest to students preparing for OI competitions, as the problems are quite interesting and fit the current trend of OI problems quite well.

We suggest reading all problem statements and we hope you'll enjoy the contest!＼

UPD: Contest is now over! Congrats to dreamoon_love_AA for placing first in the mirror, and alvingogo for winning the official contest! The problems can still be upsolved in the gym.

Link to Editorial. The editorial will be translated in a few days.