#include <algorithm>    // for std::remove_if()
#include <iostream>     // for std::cout, std::endl
#include <string>       // for std::string
#include <vector>       // for std::vector
using namespace std;

void print(const char* name, const vector<string>& v);

int main() 
{
    // Input vectors
    vector<string> a = {"the", "of"};
    vector<string> b = {"oranges", "the", "of", "apples"};

    print("a", a);
    print("b", b);

    // Use the erase-remove idiom
    a.erase(
        remove_if(
            a.begin(), 
            a.end(), 

            // This lambda returns true if current string 's'
            // (from vector 'a') is in vector 'b'. 
            [&b](const string& s) 
            {
                auto it = find(b.begin(), b.end(), s);
                return (it != b.end());
            }
        ), 

        a.end()
    );

    cout << "\nAfter removing:\n";
    print("a", a);
}


void print(const char* name, const vector<string>& v) 
{
    cout << name << " = {";
    bool first = true;
    for (const auto& s : v) 
    {
        if (first) 
        {
            first = false;
            cout << s;
        } 
        else 
        {
            cout << ", " << s;
        }
    }
    cout << "}" << endl;
}