做九度题的时候，由于数据量大，很多情况下得用scanf和printf代替cin和cout用于输入输出，不然会报错超时不能AC。
有三条建议用于提高C++的输入输出速度：
- 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;
}
九度cin/cout耗时原因
原文：http://blog.csdn.net/wtyvhreal/article/details/41910267
