What is the time complexity of the following recursive function?

int DoSomething(int n){
 if(n <= 2)
     return 1;
 else
     return (floor(sqrt(n)) + n);
}

Which of the following sorting algorithms has the lowest worst-case complexity?

Consider the CFG with { S, A, B } as the non-terminal alphabet, { a, b } as the terminal alphabet, S as the start symbol and the following set of production rules:

$$\eqalign{ & S \to bA\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,S \to aB \cr & A \to a\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,B \to b \cr & A \to aS\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,B \to bS \cr & S \to bAA\,\,\,\,\,\,\,\,\,\,\,B \to aBB \cr} $$

For the correct answer strings to the previous question, how many derivation trees are there?

Consider the CFG with { S, A, B } as the non-terminal alphabet, { a, b } as the terminal alphabet, S as the start symbol and the following set of production rules:

$$\eqalign{ & S \to bA\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,S \to aB \cr & A \to a\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,B \to b \cr & A \to aS\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,B \to bS \cr & S \to bAA\,\,\,\,\,\,\,\,\,\,\,B \to aBB \cr} $$

Which of the following strings is generated by the grammar?