best way to deal with big array or vector?

[dukevn]

So are you OK with these results? (It's still taking over 3 minutes!)
Is that a kind of processing you do often? I assume that if it was a one time deal, you'd be OK with original 11 minutes.
Text file are usually very zippable, could you try to zip your 1GB file and see how big it is? Any way you could share it?
I also assume that your lates code is in post # 31 above.

No, I do not have to do that processing often. I was actually pleased because I have learned a lot.

The text is around 200MB when in tar.bz2. How could I share it?

And yes, my latest code is in post 31.

Anyway, I need to move on. It seems to me that map is two component container. How could I get a three component container similar like that, with the first component is the first column of input file, second is second, and third is third? The reason I ask because now I want to write output like this

a1     12	1
a1     13	1
a1     14	1
a1     15	1
a1     16	1
a1     17	1
a1     20	1
a1     21	2
a1     22	2
a1     23	2
a1     24	2
a1     25	2