$ sudo apt-get update
$ sudo apt-get install clang-format-3.5 

clang-format-3.5 is installed in your system.

Make ensure the clang-format-3.5 package were installed using the commands given below,

$ sudo dpkg-query -l | grep clang-format-3.5 *

You will get with clang-format-3.5 package name, version, architecture and description in a table

clang-format-3.5 package basic information: