"John" <we**********@y ahoo.com> wrote in message
news:11******** **************@ g14g2000cwa.goo glegroups.com.. .
stupid me. I was thinking if the sets were disjoint (non-overlapping).
You are absolutely right.
Here is a better formulation of my question, I have two maps M1,M2.
I would like to do the set_union type operation on it. I can of course
make a set and put the data inside it using pair. Any other ideas
on how to do this more naturally? can maps be unioned?
If you want the union to a separate set from M1 and M2, you can do the
following:
map<key, value, comp> M1plus2;
set_union(M1.be gin(), M1.end(), M2.begin(), M2.end(), inserter(M1plus 2,
M1plus2.end()), M1plus2.value_c omp());
This finishes in O(M1.size() + M2.size()), because it always inserts new
elements at the end of the output map.
Joe Gottman