Should be a simple question: How does one print one element of a 2D vector? For example with an array you would use int myarray[3] = {4,3,1,2}; cout << myarray[0];
I think you need the at function ( a member of vector)
Google C++ vector example -there are all kinds of functionality for vectors, some you may not be aware of.
As I said, I am not a big fan of vector of vectors. Consider using a different container like <list> a double linked list, or <map> or <set>. Google these.