Ques 13 STL-quiz 1

#1

How will the answer be 0?

#2

Check the return value of set insert function in STL from here http://www.cplusplus.com/reference/set/set/insert/

You can see that it returns a pair, with its member pair::first set to an iterator pointing to either the newly inserted element or to the equivalent element already in the set.The pair::second element in the pair is set to true if a new element was inserted or false if an equivalent element already existed.

Now check if you can answer the question.