Answer:
Libraries in c++ allows us to use common functions and data structures such as vectors,queue,stack etc.You have already used iostream library by which you are taking input and printing the output with the help of cin and cout functions.
for example you should use vector library to be able to use vector in your program.
You can incorporate library in your c++ program by writing #include<library name> at the starting odf the program.
for example:-
#include<iostream> //including iostream library.
#include<queue> //including queue library.
using namespace std;
int main()
{
queue<int> q; //declaring a queue of integer type.
q.push(23);//adding 23 in the queue q.
q.push(56);//adding 56 in the queue q.
q.pop();//deleting element from the queue.
cout<<q.front()<<endl;//printing fornt of the queue..
return 0;
}
output :-56