Design and implement a web browser which supports the functionality that at any given instance you can efficiently tell the top 5 visited websites on basis of number of visits.

struct Webpage
{
    std::string url;
    size_t numberOfVisits;
};
 
struct History
{
    void visit(const std::string & url) {
    }
 
    void printTop5() {
    }
};

Any ideas?