ProveMeRight's blog

Can someone verify? that this question can be solved or it's impossble.
By ProveMeRight, history, 20 months ago, In English

let's suppose the case:

k = 1, n = 1000;

arr[] = {1,3,5,7,9,11,..........1999]

For this case, the answer can be 2^N, and according to the question we have to return an integer. Is it possible?

Please help someone.

Thank you.

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20 months ago, # |
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    20 months ago, # ^ |
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    hint4: Read the issues mentioned in the blog first, rather than rushing to growing contribution.

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      20 months ago, # ^ |
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20 months ago, # |
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Since n<=10^3 we can solve the problem in O(n^2) by the naive implementation of biginteger.

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20 months ago, # |
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Yes, it is possible. $$$2^{1000}$$$, which is the largest possible answer, has roughly $$$300$$$ digits. Multiplying numbers to get to a $$$300$$$ digits number shouldn't be too slow. If you still get TLE, you can just represent bigInt using base $$$10^{9}$$$, which would bring the number of digits down to a laughable $$$34$$$. If you are using Python then time limit shouldn't be a problem as well, as Python has built-in Karatsuba multiplication algorithm, which is fast.

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    20 months ago, # ^ |
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    Multiplying $$$k$$$ numbers (polynomials) in the case when answer has $$$n$$$ digits is $$$O(n^2)$$$. One may prove it with a reasoning simar to the one behind $$$O(n^2)$$$ knapsack on trees.

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