MikeMirzayanov's blog

Codeforces Round #241 (Div. 2)
By MikeMirzayanov, 11 years ago, translation, In English

The round will start on 08:00 (UTC) of April, 13. It will be a kind of unusual round because at first for a long time Gerald didn't work much on round. It was prepared by me (how it is interesting to write a round!), Nerevar with the help of Gerald and Fefer_Ivan-а. Maria, many thanks for translations!

It will be classical points: 500 — 1000 — 1500 — 2000 — 2500.

  • Vote: I like it
  • +135
  • Vote: I do not like it

Comments Comments (37)
| Write comment?
»
11 years ago, # |
  Vote: I like it 0 Vote: I do not like it

sounds cool! Good luck

→ Reply
»
11 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Good luck everyone

→ Reply
»
11 years ago, # |
  Vote: I like it +12 Vote: I do not like it

This round is writen by MikeMirzayanov.Sounds very good!Good luck to everyone!

→ Reply
»
11 years ago, # |
  Vote: I like it +16 Vote: I do not like it

MikeMirzayanov's round.... sounds nice! GL&&HF

→ Reply
»
11 years ago, # |
  Vote: I like it +4 Vote: I do not like it

I'm sure there will be nice questions :)

→ Reply
»
11 years ago, # |
  Vote: I like it -8 Vote: I do not like it

I new people join, What is hack?

Please help me?

→ Reply
»
11 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

I don't know, if I'm the only one, but really, it seems that problem B and Problem C are easier than problem A... :/

→ Reply
»
11 years ago, # |
  Vote: I like it +3 Vote: I do not like it

That was really funny round. Especially hacks for problem A. Also really nice tasks.

→ Reply
»
11 years ago, # |
  Vote: I like it 0 Vote: I do not like it

For C, I sorted the groups in descending order of the amount of money they paid and then the tables by their size — my soln didn't get accepted. What's the right way of solving it?

→ Reply
  • »
    »
    11 years ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    Your way is right. Sort groups in descending order of money, sort tables in ascending order by size.

    Here is my code: http://pastebin.com/JD9AZmsb

    → Reply
    • »
      »
      »
      11 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      What is the proof that Greedy works well for Problem C? I just assumed that Greedy was the right method, by intuition.

      → Reply
      • »
        »
        »
        »
        11 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        Roughly because of the fact that you cant split groups or give a table to more than 1 group.

        → Reply
      • »
        »
        »
        »
        11 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        Because, 1. You can't split the groups 2. A group holds the table till the very end

        → Reply
»
11 years ago, # |
  Vote: I like it +11 Vote: I do not like it

In problem A , I made 10 successful hacks , however my solution is wrong itself , but no one in my room hacked mine .. :D

→ Reply
»
11 years ago, # |
  Vote: I like it +7 Vote: I do not like it

It was a very good contest.............I enjoyed.........

→ Reply
»
11 years ago, # |
← Rev. 2   Vote: I like it +9 Vote: I do not like it

this round trolled me: 46 place before pretests and 542 after )

→ Reply
»
11 years ago, # |
  Vote: I like it +1 Vote: I do not like it

Can anyone give me a hint for Prob E ?

→ Reply
»
11 years ago, # |
  Vote: I like it 0 Vote: I do not like it

If we have 2 sets — a, b is it possible to insert all elements of b into a faster then b.size() * log(a.size()) ?

→ Reply
»
11 years ago, # |
  Vote: I like it +4 Vote: I do not like it

Is this possible to see what input a participant used to hack?

→ Reply
  • »
    »
    11 years ago, # ^ |
      Vote: I like it +4 Vote: I do not like it

    Yes, open http://codeforces.net/contest/416/hacks. find the row for you and double click on verdict column.

    → Reply
    • »
      »
      »
      11 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Is there any way to limit the hacks to certain user? I was trying to find the ones I used for a friend (I eventually found them all by scrolling down the page, but wondering if there's an easier way).

      → Reply
      • »
        »
        »
        »
        11 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        Try clicking on the arrow on the upper-right corner and typing "bli0042".

        → Reply
  • »
    »
    11 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    Here

    → Reply
    • »
      »
      »
      11 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Thanks a lot. My bad for not seeing it

      → Reply
»
11 years ago, # |
  Vote: I like it +14 Vote: I do not like it

Round stats

→ Reply
»
11 years ago, # |
  Vote: I like it 0 Vote: I do not like it

good contest！ I did today.

→ Reply
»
11 years ago, # |
  Vote: I like it 0 Vote: I do not like it

My greedy approach for D didn't work. Can you tell me why? 6357863

→ Reply
  • »
    »
    11 years ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    Because on the test #53 we need at least 5 sequences, but your program has written 4.

    → Reply
    • »
      »
      »
      11 years ago, # ^ |
        Vote: I like it -7 Vote: I do not like it

      Surely it's obvious. Maybe you can fix it for few so that it can be right

      → Reply
»
11 years ago, # |
  Vote: I like it +20 Vote: I do not like it

Editorials??

→ Reply
»
11 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

Since there are not any tutorial.Can anybody explain the method to solve problem D.

→ Reply