Boxer's blog

ECNA 2007 Problem H: Target Practice
By Boxer, 10 years ago, In English

Hi everyone , i'm trying to solve this problem Link

I found some discussion in this forum in topcoder Link and they suggest a dp with bitmask.

Well i'm coded a dp with bitmask but i have got TLE

Someone can help me ?

My Implementation : Ideone

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10 years ago, # |
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I'm really skeptical that this problem has a polynomial solution, so it's probably just about optimizing and pruning some type of backtracking.

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10 years ago, # |
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Your solution is ok, but you have to change your dynamic programming by a backtrack to lose the constants of access to std::map, but you have to make some pruning to speed it up.

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    10 years ago, # ^ |
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    You know, the word backtrack probably comes from the action of "tracing back" (the last few moves; note that it's 'cing', not 'cking'), not "backing track" :D

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      10 years ago, # ^ |
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      but it's backtracking, isn't it? :D

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        10 years ago, # ^ |
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        Where I live, we have many words deformed by more comfortable pronounciation (you wouldn't guess what Bluetooth is sometimes called :D). I could be wrong, of course, it's just about what makes more sense to me.

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