Anubhabghosh's blog

Why this code is giving TLE
By Anubhabghosh, history, 4 years ago, In English

Problem link: https://mirror.codeforces.com/contest/1423/problem/K

submission link: https://mirror.codeforces.com/contest/1423/submission/97905194

I don't understand why I am getting TLE can anyone help?

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4 years ago, # |
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Instead of running an upper bound for each case, maybe try keeping an array where a[i] is the number of primes till i.

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4 years ago, # |
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Replace cout with printf. std::cout is too slow for printing.

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    4 years ago, # ^ |
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    That's a myth. With non-synchronisation with stdio, cout is as fast as printf, if not faster.

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4 years ago, # |
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First of all, cout.tie(NULL) doesn't do anything (literally).

Your code gets TLE because endl is slow (and unnecessary here).

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    4 years ago, # ^ |
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    Thank you very much. Now I understand why it was giving TLE. After replacing endl with "\n" now it is giving ac.

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