timer.h

#include <iostream>
#include <ctime>
#include <unistd.h>
using namespace std;
int timer()
{
  /*The while loop should run for 5 mins(300 secs).
   time(0) gives the current time, because we are using the library ctime.*/
  int total_time = 300;
  time_t current_time = time(0);
  while(time(0)-current_time<total_time)
  {
    //Suppose to execute the main file.
  }
  cout<<"Game Over, Your time is up!!!";
}