How do I remove duplicates with std::vector?

In C++, you can remove duplicates from a std::vector by using the `std::sort` and `std::unique` algorithms. This approach effectively combines sorting the elements and then removing consecutive duplicate entries.

Here’s an example:


        #include 
        #include 
        #include 

        int main() {
            std::vector vec = {1, 2, 3, 2, 1, 4, 5};

            // Sort the vector
            std::sort(vec.begin(), vec.end());

            // Remove duplicates
            auto last = std::unique(vec.begin(), vec.end());
            vec.erase(last, vec.end());

            // Output the results
            for (int n : vec) {
                std::cout << n << " ";
            }
            return 0;
        }