I wrote two different codes, which differs only on order of headers. Two codes are like these:

#include <stdio.h>
#include <algorithm>
....(blahblah)....

2.

#include <algorithm>
#include <stdio.h>
....(blahblah)....

Note: At (blahblah) part, there are 9 millions scanf("%d", &t) operations. Compilation options are both GNU C++14. (GNU C++14 6.2.0, which is used on Codeforces.)

For my opinion, this two code should exactly do the same operations.

But, 1st code gives 1.6ms / 2ms AC, and 2nd code gives TLE. This issue is not about server status, it's still same during many submits.

Can someone help me about what's going on here?

Note : It's not 1.6ms / 2ms, It's 1.6s / 2s