#include <TFile.h>
#include <TH1F.h>
#include <TString.h>

#include <iostream>

int main()
{
  TFile f("test.root","RECREATE");

  for(uint i=0;i<200;i++)
    {
      std::cout << i << std::endl;
      TDirectory *d=f.mkdir(TString::Format("selection%d",i).Data());
      for(uint j=0;j<200;j++)
	{
	  TH1F *h=new TH1F(TString::Format("test%d",j),"",10,-3,3);
	  h->FillRandom("gaus");
	  h->SetDirectory(d);
	}
    }
  clock_t start = std::clock();

  std::cout << "Start writing" << std::endl;
  f.Write();
  clock_t write = std::clock();

  std::cout << "Start closing" << std::endl;
  f.Close();
  clock_t close =std::clock();

  double elapsed_secs_1 = double(write - start) / CLOCKS_PER_SEC;
  double elapsed_secs_2 = double(close - write) / CLOCKS_PER_SEC;
  std::cout << "Time to write: " << elapsed_secs_1 << " s" << std::endl;
  std::cout << "Time to close: " << elapsed_secs_2 << " s" << std::endl;

  return 0;
}