Installing root on ubuntu 18.04

I am having extreme difficulty trying to work out how to install root on ubuntu 18.04. I am trying to install version 5.34/32, as I understand the code I need to run does not work on root 6. Can anyone advise on how to overcome this error? This occurs using both the ./configure;make and CMake installation methods.

In file included from cint/cint/src/dict/libstrm.h:37:0,
                 from cint/cint/src/dict/libstrm.cxx:14:
cint/cint/lib/stream/iostrm.h:24:10: fatal error: iostream.h: No such file or directory
 #include <iostream.h>
compilation terminated.
Makefile:631: recipe for target 'cint/cint/src/dict/libstrm.o' failed
make: *** [cint/cint/src/dict/libstrm.o] Error 1

Try this:

I doubt that, and we’re here to help fix any issues that might come up! On the other hand 5.34/32 is really old, Ubuntu 18.04 is fairly recent, not a good combination…

Hiding this as per Newbie section rules.