klamathix's blog

GP of ICL 2013, problem F (Cost of The Question)
By klamathix, 10 years ago, In English

Hello.

I was upsolving some problems from the Open Cup GP of ICL 2013. When I wanted to submit problem F (Cost of the Question), its name in the submission window included "NOT_SOLVABLE". However, I got Accepted. So can anyone who has participated in that contest please clarify what does "NOT_SOLVABLE" mean? Was there a technical problem with this task's grader at some point? Or is the problem literally not solvable conceptually and the judge solution is wrong? The problem seems to have been solved during the contest and it's still in the standings.

Thank you.

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10 years ago, # |
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Problemsetters thought that they could solve a task, but their greedy solution was in fact wrong. Several teams on onsite contest as well as in online contest also submitted this greedy solution (without proving it).

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    10 years ago, # ^ |
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    And as I suspected, so is my greedy solution :). Thank you very much!

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