Welcome to the 2020 Cameron Hall Charity UnVigil UnContest.

This contest is a little different to our other contests and comprises of 12 questions released in three batches of four. Thanks to chibi, Tommoa, Seamooo and FarmBoy2222 for writing and testing these problems.

All questions are worth one point. You can attempt any released question at any time until the contest closes on Saturday.

All input and output will be done via the standard input and output streams respectively.

Standard Rules

• Refrain from discussion the questions with other competitors. Feel free to reach out to us on our discord for clarifications.
• You may copy and paste code from your code library.
• The scoreboard is provisional until the winner is announced. The contest writers reserve the right to add test data to break any incorrect or time limit exceeded solutions.

UnVigil Perks

• All donations to the event are lodged online as tokens in a wallet. These tokens can be used at any Charity UnVigil event and not just our contest. Donate [https://charityunvigil.online/]
• To encourage donations to Zonta House, we are allowing competitors to make the contest easier for themselves. Perks are available for purchase at the following times. You will need to let us know in our discord (https://discord.gg/2WaTYnj) if you decide to donate.
  • Wednesday 13/5 - 5-10 pm
  • Thursday 14/5 - 5-10 pm
  • Friday 15/5 - 5-10pm
  • Saturday 16/5 - 9 am -12 pm Perks are 'purchased' by requesting them in the Perk Channel A committee member will handle removing the credits used from your donation wallet and carry out whatever benefits the perk gives you The following perks are available: Receive a hint $2 Raise time-limit for a problem $4 See all test-data for a problem $4 Receive an example implementation for a problem (instant solve) $10

Some Advice

• Read the bounds, read the time limit, and DO COMPLEXITY ANALYSIS. Do not waste time on a solution that will definitely get time limit exceeded.
• Read every question.
• Try not to get stuck solving a question if there are others you can work on.
• If you get a wrong answer, try debugging using your own test cases.

We guaranteed that all problems are solvable in C/C++. Due to the relative efficiency of some languages, we do not guarantee any other languages are viable. Problems are almost always solvable in Java. Problems are occasionally solvable in Python.

This contest is not rated.