Can someone plz explain how to do this problem. Problem from the recent hackerearth contest
You are given n ($$$1$$$ $$$\le$$$ $$$n$$$ $$$\le$$$ $$$300000$$$) queries. Each query is one of $$$3$$$ types:
add pair ($$$a$$$, $$$b$$$) to the set. ($$$-10^9$$$ $$$\le$$$ $$$a, b$$$ $$$\le$$$ $$$10^9$$$)
remove a pair added in query $$$index$$$ (All queries are numbered with integers from $$$1$$$ to $$$n$$$).
For a given integer $$$A$$$ find the maximal value $$$a·A + b$$$ over all pairs ($$$a$$$, $$$b$$$) from the set. ($$$-10^9$$$ $$$\le$$$ $$$A$$$ $$$\le$$$ $$$10^9$$$). It is guaranteed that the set of pair will not be empty.
INPUT.
The first line contains integer $$$n$$$ ($$$1$$$ $$$\le$$$ $$$n$$$ $$$\le$$$ $$$3·10^5$$$) — the number of queries.
Each of next $$$n$$$ lines starts with integer $$$op$$$ ($$$1$$$ $$$\le$$$ $$$op$$$ $$$\le$$$ $$$3$$$) — the type of query.
OUTPUT
For each query of $$$3$$$ type print on a separate line the maximal value of $$$a·A + b$$$. It is guaranteed that the set of pair will not be empty.
