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Me_iS_NooB's blog

Why time limited exeeded in my O(nlogn) solution
By Me_iS_NooB, history, 2 years ago, In English

i was trying to solve this problem:- https://codeforces.me/contest/1801/problem/B

My solution :- https://codeforces.me/contest/1801/submission/278323418

In my solution i wrote a O(nlogn) solution and the judge is showing time limit exceeded. But in editorial the solution given is O(nlogn) and that is getting passed. I am having trouble understanding how this is happening.

plzz help :,(

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2 years ago, hide # |
 
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set has its own object function lower_bound to use. Do not use lower_bound in algorithm.h, as performing it on set would most of the time cause an $$$\mathcal{O}(n)$$$ time complexity per call.

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    2 years ago, hide # ^ |
     
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    Resubmitted but WA: 278326222. Well, since I didn't solve this one yet, I wouldn't give further advice, but at least the TLE is dealt with.

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    2 years ago, hide # ^ |
     
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    why lower_bound that isn't method in set object act in o(n)

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      2 years ago, hide # ^ |
       
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      Please refer to this:

      However, if ForwardIt is not a LegacyRandomAccessIterator, the number of iterator increments is linear in $$$N$$$.

      Notably, std::map, std::multimap, std::set, and std::multiset iterators are not random access, and so their member lower_bound functions should be preferred.

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2 years ago, hide # |
 
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Cuz your sol is not O(nlogn), dummy.

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