on root and gcc

[Char Aznable]

I just installed OS X on my PB and was trying to install gcc and it dawned on me: during the installation process, i was never asked for a root password, just my user password. Now I can't untar on root because it tells me the folders it wants to write to are protected. If I try to su as root using my user password, it won't let me.

What to do?
What to do?

I really need g77