#include <iostream>
#include <unistd.h>
#include <sys/wait.h>
#include <vector>
#include <algorithm>
#include <cstdlib>
#include <ctime>



	void random_task(int id)
	{
       srand(time(0));
       int delay = 1 + rand() % 3;

           std::cout << "PID " << getpid()
             << ",PPID " << getppid() 
                << " task " << id
                 << " delay " << delay << "s\n";
                   sleep(delay);
	                       }

int main()
{
    int total = 6; //tasks
        int levels = 2; //workers
            pid_t root = getpid();
               std::vector<pid_t> pids;
               int worker_id;
               int worker_count = levels;
             // Root spawns children and stores PIDs
               for (int i = 0; i < levels; ++i)
                               {
               if (getpid() != root) {
                break;
                 //_exit(0);
                                        	    	}
                pid_t pid = fork();
                if (pid == 0)
                                  {
               std::cout << "["<<getpid() << "," << i << std::endl;
               worker_id=i;
                break;
                  	                                   }
                       else {
                pids.push_back(pid);
                             }
                                                           }
 // ROOT reaping loop
     if (getpid() == root)
         {
                 int status;

                         while (1)
                                 {
                                             pid_t finished = waitpid(-1, &status, 0);

                                                         if (finished > 0)
                                                                     {
                                                                                     std::cout << "Reaped PID " << finished << "\n";

                                                                                                     pids.erase(std::remove(pids.begin(),
                                                                                                                                            pids.end(),
                                                                                                                                                                                   finished),
                                                                                                                                                                                                              pids.end());
                                                                                                                                                                                                                              continue;
                                                                                                                                                                                                                                          }
                                                                                                                                                                                                                                                      if (finished == -1 && errno == ECHILD)
                break;
                break;
                                                      }
                                              }
                                                  else
                                                      {
                                                          // Work distribution (modulo)
                                                              for (int i = 0; i < total; ++i) {
                                                                      if (i % worker_count == worker_id) {
                                                                                  random_task(i);
                                                                                  	}
                                                                                  	    }
                                                                                  	        }

                                                                                  	            return 0;
                                                                                  	            }