Question

c++

will rate if correct answers r provided

When would you use an unordered set? When the elements are hashable When you don't want to allow duplicates. When you don't need the elements sorted. All of the above None of the above. Which of the following algorithms are faster with a sorted vector (instead of an unordered one)? transform COunt find None of the above What is the equivalent iterator to std::back inserter for std::set? std: back inserter std iterator std inserter There is no output iterator generator for std set Why do some people inline their constructors? Because the users of a class need to know the initializer list Because inlining is sometimes generates faster code Because it doesn't matter is code is in the header or the implementation file None of the above

Answer 1

1. (c) The unordered set is the value of an element which is it's key at the same time. So that it can uniquely define the value and no chance of duplicate elements. In the unordered list, it does not sort the elements in any particular order. And it is the same in a hash that its value is also key for it.

so the answer will (C) be all of these

2.(C) Definitely Find will be faster because transform and count perform on all the elements and the find will be performing till it not find it's an element for what it is searching for and when it got it's key then it will exit and as the element are sorted so you can easily apply binary search algorithm which can perform find operation in less time.

so, the answer is (C) find

3. (C) std:: inserter because the set has no push_back. and we can determine the position of an element with the help of comparator of the set.

so answer is (C) std:: inserter

4. (B) Inlining is nothing but a single line statement which requests to the constructor to execute. We Use the process of inlining to fast the execution.

so answer is (B) because inlining is sometimes generated faster code