Faces with the same single geometry

Hi Ming,

Frankly speaking, don’t see an issue here – just iterate and classify.
You might want to distribute into the map like:
to enable faster classification per surface type. Then compare a definition of a current surface with First()’s of every list. If it matches – append to that list, if not – init a new list and add it into the top list. To compare definitions of surfaces you might use:

Handle(Geom_Surface) aHS1 = …, aHS2 = …;
const Geom_Surface& aS1 = *(aHS1.operator->());
const Geom_Surface& aS2 = *(aHS2.operator->());

if (aS1 == aS2) {
…
}

Be aware that you will compare doubles, so this can be prone to accuracy problems in general case.

Good luck.
Roman