In Codeforces Round 635 (Div. 2) ,I tried to hack this submission 76834239 but failed.
His time complexity seems to be $$$O(Td)$$$
The hack I used was
$$$1000$$$
$$$1\space 1 \space 1\space 10^9$$$
$$$1\space 1\space 1\space 10^9$$$
$$$1\space 1\space 1\space 10^9$$$
$$$\dots$$$
Why would this fail?
Does it have something to do with the language he chose?
I think it's because on Codeforces, O2 is always turned on.
On my computer, if I choose O2, it seems that the complexity has been optimized to $O(1)$。
Thank you very much.