It's just a fundamental mistake to lump them together. They are not the same programming language. What you're effectively doing when you say "C/C++" is promulgating a misnomer.

On a forum that...

My first guess is you're using Visual C++ :) It compiles fine with g++, maybe try:

struct process
{
int pid; // process id
char* file_name; // file name of the process to be run
int cpu_time;...