could they have had individual namespaces for string, vector, list etc
That would be silly. Those are all part of the standard library, aka std namespace. Shouldn't ever cause you a problem unless you stick it in the global scope.
explain why the using namespace std pollutes the namespace
For example, if you're using another library that has it's own version of a vector with some extra functionality or something, if you stick the std namespace and the library namespace all in global scope, when you try to use a vector your compiler won't have any idea which one you mean.
ohh ok guys.. that makes sense... thanks
I just found another problem....
when I run the program... this runs normally until it the end where it should give the oldest age... what happens... is that I get a bunch of characters... and obviously I do not get the oldest person...