Blog comments

In attempt to improve the asking-for-help blogs here in CF, I'll start with a summary of good and bad points of your blog.

Good:

• Stated the question clearly and provided an example

• Reasonable English, formatting and politeness

Bad:

• You should link the problem and editorial instead of just giving its code

• Ideally give a summary of the solution as you understand it. This will save time and also make it clear if you misunderstood some part of the solution.

Actual help

In the editorial $$$m$$$ indicates the total number of kingdoms across all lists. In your example case you would have $$$n$$$ lists of $$$n$$$ kingdoms so a test of size $$$n^2$$$ — which is not allowed. You can see the constraints say that the total number of kingdoms in all lists across all tests is at most $$$10^5$$$, while $$$n^2$$$ in your test would be $$$10^{10}$$$.

So if your example were valid, it would indeed be $$$O(n^2)$$$, but we would also have $$$m=n^2$$$ and so $$$O(n+m)=O(n+n^2)=O(n^2)$$$ would be the same thing. The claim that it is $$$O(n+m)$$$ is indeed correct.

Thank you for your comments and I will keep in mind your comments.

I had misunderstood that constraints "the total number of kingdoms in all lists across all tests is at most 10^5"

Thank you very much.