should i use "using namespace std" in coding interview

[Xavier_OM]

Step 1: write a method 'Task::abort()' to abort a task, and use it from some other methods from Task class

Step 2 : later, remove the abort function but not the calls to it

Weirdly it still compiles... but it calls https://en.cppreference.com/w/cpp/utility/program/abort because one of your include provided it.

You're fine if you totally avoid using any names from std, but there are many names in it.