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Junior Challenge 2017 Day 1 + Round #45 (Div. 1.5)
By csacademy, 7 years ago, In English

Junior Challenge is a yearly contest organised by volunteers from the Romanian programming community. The contest is addressed to middle school students who want to prepare for the Junior Balkan Olympiad in Informatics, and starting this year, the European Junior Olympiad in Informatics.

This is the first international edition of the contest. There will be two separate competition days, and the rounds will be unrated. The first round takes place on Sunday, September/03/2017 15:00 (UTC).

Contest format:

  • You will have to solve 4 tasks in 4 hours.
  • The first task will be the easiest one, the other three will be in random order.
  • There will be full feedback throughout the entire contest.
  • The tasks will have partial scoring. The maximum score for each problem will be 100 points.
  • There will be no tie breaker, so two users having the same total score at the end of the contest will share the same place in the standings.

Many thanks to Andrei1998, bciobanu, tamionv, geniucos and george_stelian for authoring and preparing the tasks.

Round #45 (Div. 1.5)

In parallel with Junior Challenge, we will organise two CS Academy rounds, that will be rated for everyone with a rating below 1775 (this includes yellows). The CS Academy contests will consist of all the problems in Junior Challenge, plus some extra easy ones. The corresponding Round #45 starts at the same time, on Sunday, September/03/2017 15:00 (UTC).

Contest format:

  • You will have to solve 6 tasks in 2 hours.
  • There will be full feedback throughout the entire contest.
  • Tasks will not have partial scoring, so you need to pass all test cases for a solution to count (ACM-ICPC-style).
  • Tasks will have dynamic scores. According to the number of users that solve a problem the score will vary between 100 and 1000.
  • Besides the score, each user will also get a penalty that is going to be used as a tie breaker.

About the penalty system:

  • Computed using the following formula: the minute of the last accepted solution + the penalty for each solved task. The penalty for a solved task is equal to log2 (no_of_submissions) * 5.
  • Solutions that don't compile or don't pass the example test cases are ignored.
  • Once you solve a task you can still resubmit. All the following solutions will be ignored for both the score and the penalty.

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  • Vote: I like it
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7 years ago, # |
  Vote: I like it +22 Vote: I do not like it

Just a reminder, the contests start in 8 hours.

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7 years ago, # |
  Vote: I like it 0 Vote: I do not like it

how to solve "Palindromic Tree" ?

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    7 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    "There is a parallel round going on with the same problems (junior challenge) -- please don't discuss the problems [...] for another 2 hours"

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    7 years ago, # ^ |
      Vote: I like it +9 Vote: I do not like it

    The contest is over. You can check out all the solutions here

    The solution only for palindromic tree is here

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7 years ago, # |
  Vote: I like it +5 Vote: I do not like it

I misread the Remove Update problem into this:

For each update, you can choose to NOT add x to an element in [L, R]

How can this problem be solved ?

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