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Lightoj 1021 — Painful Bases
By sifat_15, history, 7 years ago, In English

Can Anyone give the idea for the following Problem LOJ — 1021 Painful Bases

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7 years ago, # |
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Auto comment: topic has been updated by sifat_15 (previous revision, new revision, compare).

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7 years ago, # |
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Let dp[mask][rem] represent the number of permutations of the digits corresponding to the indices of set bits in the input string and having remainder rem when divided with k.

for all i such that i is not set in mask:
       dp[mask | (1 << i)][(rem * base + digit[i]) % k] += dp[mask][rem]

Code

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    7 years ago, # ^ |
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    I don't understand how the mask work here (I mean how do I get all the permutation)! please describe it a little bit more. And what would be the complexity of this code?

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    5 years ago, # ^ |
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    Your code is so beautiful and self-explanatory. Thanks!

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    4 years ago, # ^ |
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    Isn't the complexity of your code 2^N * N * K * T? Which is almost 2*10^9.

    How does it avoid TLE? :o

    The complexity of my code is same too. I coded with this logic because I had no option left during a practice contest. I was surprised to see this getting Accepted.

    Or am I missing something in this complexity calculation?

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    2 years ago, # ^ |
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    is rem * base always valid ie are all the digits of (rem*base) fall into 0 to base-1?

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