Fedora – Install another gcc version

gcc-4.7.2 was released 3 days ago on September 20th. It won't have made it into the debian repos yet (See update2, thanks derobert).

According to the release notes it is a bug-fixing release so will probably use the same library versions as the previous, 4.7.1, release. So, since 4.7.1 is in the repos, install it to get all the dependencies sorted, then if you really really need the latest version, download the source and compile following the instructions from the gcc website.

UPDATE:

You seem to have a problem with your source.lst. As a workaround, try downloading the package here and installing using dkpg -i gcc_4.7.1-1_amd64.deb.

UPDATE 2:

As @derobert points out below, 4.7.2 is indeed in the experimental repo. So, adapt the instructions from the post you linked to:

Your /etc/apt/sources.list should look something like this:

deb local.debian.mirror squeeze main
deb local.debian.mirror unstable main

while your /etc/apt/preferences should look something like this:

Package: *
Pin: release n=squeeze
Pin-Priority: 900

Package: *
Pin: release n=unstable
Pin-Priority: 200

Then install using apt-get install gcc-4.7/unstable.

As both jordanm and the original tutorial you linked to mention, this is not a very good idea. Make sure to point your sources back to stable once you're finished.

You'll probably end up spending an awful lot of time getting GCC 4.7 built on your current system, and in the end you still won't be sure of the result: your school's computers' version of GCC may include distribution patches or even local changes which your version won't have.

I would suggest instead that you run the distribution your school is using in a VM. Your school is using RHEL, and you can too: you can get a no-cost developer subscription from Red Hat Developers; once you've got your subscription, you can download ISOs of any still-supported version of RHEL, so you should be able to install the same version as used on the school computers.

In any case since this is for grading purposes you should always check your code on the school computers before submitting it!