CSS selector grouping algorithm implemented in C++ -

I am developing a CSS Minator which will work in collaboration with other designers with general announcements. I have written a CSS parser which is functional, but what is my problem; Based on common announcements, think the programmer group together with the selectors in the best possible way. Right now, with a parser selector name (i.e., H1, H6, Div, etc.), a consultant interprets a CSS block object as argument. Then it parses declarations from the selector, divides each one into the property / value pair (i.e. Margin: 0), and assign them a map and gtc: < / Code> Member variables in that object I think what I have to do, loop through objects, check general declarations, and then group them all .. But how can I do this better so that the extra Do not have the group Can groups join? Or is not every group made around a declaration, but many? Hopefully I am understanding ... if not, please say this in comments and I will try to explain it more clearly.