没有匹配的 function 来调用。 C++ STL

Question

I'm new to C++ STL. I'm writing a function to check whether one vector is an subset of another(Duplicate elements also count) and print 'Yes' or 'No'. I have come up with the following code:

void checkMagazine(vector<string> magazine, vector<string> note) {
    vector<string>::iterator a;
    for(int i=0;i<note.size();i++)
    {
        a=find(magazine.begin(),magazine.end(),note[i]);
        if(a==magazine.end())
        {
            printf("No");
            return;
        }else magazine.erase(a-magazine.begin());
    }
    printf("Yes");
}

But,I'm getting the following compilation error:

error: no matching function for call to ‘std::vector<std::__cxx11::basic_string<char>
>::erase(__gnu_cxx::__normal_iterator<std::__cxx11::basic_string<char>*,
std::vector<std::__cxx11::basic_string<char> > >::difference_type)’
         }else magazine.erase(a-magazine.begin());

I'm trying to use erase to delete the found element in magazine.Is there some problem with the type of declaration of the iterator? Why is this happening? And also if there are alternate methods/logic/inbuilt-functions to get the required job done using STL, Please let me know since I'm new to this and trying to learn it.

Answer 1

erase takes an iterator. You have that iterator, it's called a . But you then convert the iterator a into an offset relative to begin() . erase does not have an overload which takes an offset.

The Standard Library has alternatives if the vectors would be sorted, but we don't see the calling code so we can't assume that.