I tried to install g++ using packages from another user. offline..but there were errors. After connecting to the net I tried to install using sudo apt-get install g++, but it gave the following output:

gstreamer0.10-alsa is already the newest version.
qtdeclarative5-ubuntu-ui-extras-browser-plugin is already the newest version.
python-gconf is already the newest version.
gstreamer0.10-tools is already the newest version.
libglib2.0-0 is already the newest version.
gir1.2-peas-1.0 is already the newest version.
libatk-bridge2.0-0 is already the newest version.
gnome-session-bin is already the newest version.
libgomp1 is already the newest version.
libmessaging-menu0 is already the newest version.
usb-creator-gtk is already the newest version.
libgnome-desktop-3-7 is already the newest version.
software-properties-gtk is already the newest version.
gnome-control-center-shared-data is already the newest version.
unity-scope-gourmet is already the newest version.
libcupsimage2 is already the newest version.
growisofs is already the newest version.
libjson-glib-1.0-common is already the newest version.
activity-log-manager is already the newest version.
libio-string-perl is already the newest version.
qtdeclarative5-qtfeedback-plugin is already the newest version.
gnome-power-manager is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

and many more lines like this....but g++ is still not installed