It happened during last Div.4

In this submission in compilation log you can see only warnings, no errors, but verdict is CE

So experimentally I figured out that an error in line 1285, ofc locally it works good with C++17:

constexpr auto darr = array<pair<int, int>, 4>{{{1, 0}, {0, 1}, {-1, 0}, {0, -1}}};

Will be nice if codeforces show full compilation log or somehow print errors first

Like cf-tool, but in python and single file, so you dont need to install anything

Link: https://github.com/elseecay/cf-assist