Rotate M*N matrix 90 Degrees Clockwise ,C++

I am trying to rotate a vvc

vector of Vectors of chars.

I made a 2d vector matrix setup. right now the matrix takes input from a file, I use vector.push_back(c) to add the characters to the vvc; An example of the vvc array would be something like this

aaaaa
azzza
azaza
azzza
azaaa
azaaa
azaaa
aaaaa

I have the vvc setup, But I am trying to rotate it 90 degrees. I rotated it 90 degrees counter clockwise but I need to rotate it 90 degrees clockwise.

as of right now my code does this

90 counter clock
aaaaaaaa
azzzzzza
azazaaaa
azzzaaaa
aaaaaaaa

and it does it through this loop;

cout <<"\n90 counter clock"<<endl;
    for (size_t colNo = 0; colNo < kvsize2; colNo++)
    {
        for (const auto &row : twovector)
        {
            char colVal = row.at(colNo);
            cout << colVal;
        }
        cout << endl;
    }

i am kind of new to C++ and I am just learning about vectors, and the Auto loop function.

trying to do a decriment loop almost works, but keeps throwing me into a segfault.

I have been stuck on this problem for the past 6 hours and I am starting to get really frustrated.

If anyone has any tips or suggestions on how to rotate a M*N 2d vector array

vector<vector<char>> twovector; // 2d array 

that would be really really helpful.

thanks