how to compare two std::set?

Question

I do such comparison of two std::set

#include 
#include 
using namespace std;

#include 
#include 

        

Answer 1

There are several set operations in C++ standard library header .

std::set_difference gives those elements that are in set 1 but not set 2.

std::set_intersection gives those elements that are in both sets.

std::set_symmetric_difference gives those elements that appear in one of the sets but not both.

std::set_union gives those elements that are in either set 1 or set 2.

The algorithms above can also be applied to STL containers other than std::set, but the containers have to be sorted first (std::set is sorted by default).