Today, I had spent hours trying to solve problem : (https://codeforces.me/contest/1334/problem/C) and submitted several solutions with an O(n) complexity, but I kept getting a TLE. After some further inspection, I changed from using cin to scanf, and my solution was finally accepted. While it's well-known that scanf is slightly faster than cin, I was surprised by how much of a difference it actually made in this case.
TLE Code : 284211972 Accepted Code : 284212724
This blog may not be overly educational, but I just want to highlight that even a O(n) solution can lead to a TLE error. Understanding this can help you avoid the frustration and wasted time that I experienced.
ios::sync_with_stdio(false);cin.tie(nullptr); cout.tie(nullptr);
Use this if you want to use cin/cout
what does
cout.tie(nullptr)do?explanation
cout = Output + cout.flush(). But if you use cout.tie(nullptr) it will untie the cin with cout. So cout = Output only. In interective problems if you don't use cout.tie(nullptr); you don't have to use flush manually as it will be done automatically.
Using this will help a lot with time complexity specially when you have multiple test cases.
And forgive my poor English
no, it's all about
cin.tie(nullptr);as far as i knowI thought everyone learns to put
cin.tie(0) -> sync_with_stdio(0)in their code the first day they start cp.Guess not :/
I know thats a fundamental thing in CP but I never thought that it would matters that much but I guess im wrong lol.