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Codeforces Beta Round 31 (Div. 2, Codeforces format)
By RAD, 14 years ago, translation, In English
Hello everyone on Codeforces Beta Round 31 (Div. 2, Codeforces format)

Round was prepared by: Mike Mirzayanov, Dmitry Matov, Max Ivanov and me.

Good luck!
Artem Rakhov and Codeforces team

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Comments Comments (39)
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14 years ago, # |
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I was getting PE on the problem D, I cant figure it out why! Can I put end lines on the outputs?
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  • 14 years ago, # ^ |
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    I received PE at first problem, when actualy it was an WA. Maybe the same happened to you. 
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    • 14 years ago, # ^ |
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      Yup, me too, i got PE but it was actually WA. Admins should fix that.
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      • 14 years ago, # ^ |
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        me too, i was typing a[i] instead of indexes i, you should fix it 
        it was WA and not PE
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  • 14 years ago, # ^ |
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    I got many PE when I submitted via uploading source file, and got AC using CTRL-C + CTRL-V. I think it is a terrible bug.
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14 years ago, # |
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i failed D at test 9. does anyone have some test case?
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  • 14 years ago, # ^ |
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    Some big test. The answer is 0.
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  • 14 years ago, # ^ |
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    WA at test 4....

    The text say, Breaks are given in arbitrary order.

    will some test case like this?
    2 2 2
    0 1 1 1
    1 0 1 2
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    • 14 years ago, # ^ |
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      Yes...
      I make one more for loop to calculate by force, then i got an Accept.
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14 years ago, # |
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Hello! I have a question. Can somebody give me some "difficults" test cases for problem E? I have Wrong Answear on test 11 and I have no ideea why. Thank you very much
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  • 14 years ago, # ^ |
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    Do you use 64-bit type?
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    • 14 years ago, # ^ |
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      I don't know how you solved the problem, but in my solution there was no need for 64-bit integers(because i didn't keep the numbers in any variables). Anyway, i'm not very sure if my solution is right, this is why i am asking for some tests:) Thx
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      • 14 years ago, # ^ |
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        Test #11
        10
89959999998998796989
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        • 14 years ago, # ^ |
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          What would be a correct answer for:

          3
          000999

          ?
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          • 14 years ago, # ^ |
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            HHHMMM for a total of 999
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            • 14 years ago, # ^ |
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              My code fails on the 4 test case, I tried a lot of test cases here and they seem to be correct :/
              The input example:
              1234
              The total is: 12 + 34?
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        • 14 years ago, # ^ |
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          Can you give me a possible valid solution or the the total sum aquired by those 2 because i still can't find the error?
          Thx:)
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          • 14 years ago, # ^ |
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            Test:
            10
            89959999998998796989
            Possible solution is (sum = 18995998865):
            HHHHHHMMMMHMMHHMHMMM


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            • 14 years ago, # ^ |
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              My algorithm gives the same solution and its failing on test 4 :/, anyone got any other test?
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            • 14 years ago, # ^ |
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              Hehe, i finally solved the problem. Thx man!! By the way: what is the official complexity of the problem? O( n^2) ?
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14 years ago, # |
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Hey can someone give test num 26 for problem E. Thanks :)
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14 years ago, # |
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I cant figure what is wrong with my D :/, tried a lot of tests here and all of them are ok, does anyone knows the test number 4? (its giving me PE, but I guess its WA)
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14 years ago, # |
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D test 9....anyone have the test case ?
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  • 14 years ago, # ^ |
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    Some big test. The answer is 0.
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    • 14 years ago, # ^ |
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      How can it be 0?

      "It is guaranteed that the set of breaks is correct, i.e. there is some order of the given breaks that each next break divides exactly one part of the bar into two non-empty parts.
      Output

      Output n + 1 numbers — areas of the resulting parts in the increasing order."

      N is at least 1, and you cant break it on empty parts!

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14 years ago, # |
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Can problem D be done with DFS/BFS ? We have a break as a wall between two pieces .
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  • 14 years ago, # ^ |
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    You could simplify the problem int the following way: 
    extend our map to the sizes (2N)x(2N). Now you may use the whole rows and columns for a walls.

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14 years ago, # |
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Can anybody explain how problem E is solved please?

I'm using DP. The parameters are (index, player1 result, player2 result, nTurns for player1, nTurns for player2)

but I'm memorizing only on index and player1 result, as the rest can be calculated through those two. Player1 result is too large so i'm memorizing in map. Sure that gives me TLE on test case 14.

What can I do? Thanks very much.
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  • 14 years ago, # ^ |
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    Try DP: d[nTurns1][nTurns2] = maximum_possible_sum. Note that we can rid of the other parameters: at current step d[nTurns1][nTurns2] we select whom to give (nTurns1+nTurns2)-th digit of the number. It's easy to understand that following strategy doesn't depend on current digits, so we can add 10^{n-nTurns1} * s[nTurns1+nTurns2] to the value d[nTurns1+1][nTurns2] to best answer if we give current digit to Homer. Similar formula is in the case of Marge. Select maximum of these two values to obtain value for current d[nTurns1][nTurns2].
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14 years ago, # |
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what is the test case 8 of problem b????? please give with its answer too. :(
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14 years ago, # |
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what is the test case 11 of problem E?????
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