Though my question is very specific, do let me know the case for other companies as well.

Question: Is having mastery over STL nuances necessary to ace the phone round ?

Let me give one example -

for (int i=5; i<v.size()-10; i++)                // Snippet-1
{
	v[i] = 20;      
}

v/s

std::fill(v.begin()+5, v.end()-10, 20);            // Snippet-2

Will Snippet-1 put me at a disadvantage when compared to Snippet-2 ?

Here is the screeshot of various concepts . Are we expected to be proficient in all these as well ?