九度cin/cout耗時原因__cin

做九度題的時候，由於資料量大，很多情況下得用scanf和printf代替cin和cout用於輸入輸出，不然會報錯逾時不能AC。

有三條建議用於提高C++的輸入輸出速度： At the first line in main function,add :std::ios_base::sync_with_stdio(false).which cancel theSynchronization between <iostream> and <cstdio>; At the second line in main function,add: std::cin.tie(0).which leads to that cin ties nothing.cin ties cout at first. For all endl, use '\n' or"\n" instead.

#include<algorithm>  #include<cstring>  using namespace std;  int main()  {      std::ios::sync_with_stdio(false);      cin.tie(0);      int n,m;      cin>>n>>m;      cout<<n<<" "<<m<<"\n";      return 0;  }