Loop runtime question

I had an exam today and I feel that I did pretty well, except I could not for the life of me figure out what appears to be an unbelievably simple question.

What is the justification for the running time of this loop?

I don’t understand why the running time of the following loop is n+2 ? Also why the running time of the statements inside the loop is n+1 ?

What is the difference between ref and out in runtime?

C# provides the ref and the out keyword to make arguments to be passed by reference. The semantic of the two is very similar. The only difference is in the initialization of the flaged variable:

Do today’s modern compilers perform run time checks?

This is regarding compilers.

Do today’s modern compilers perform run time checks?

This is regarding compilers.

Do today’s modern compilers perform run time checks?

This is regarding compilers.

A little confused with virtual functions

Please see the following code:

Is it a good practice to use suppress warnings in your code?

I use @SuppressWarnings("unchecked") and @SuppressWarnings("null") mostly above methods to let the code compile without any warnings but I have my doubts. Found this Stackoverflow question. Jon Skeet wrote an answer to it which I find intriguing.

Unable to connect to Google Collab Pro. Unable to assign CPU runtime. Getting “Failed to assign a backend” Sorry, no backends avialable

I have been using Google Colab for free for a couple month and earlier today. Opened up a new browser tab to look at another notebook and got the following error: “Failed to assign a backend” Sorry, no backends availabe.