#include "TFile.h"
#include "TTree.h"

#include <iostream>

#define _MAX_POSSIBLE_G1XCL_ 9999999

int Analyze_LHE()
{
  TFile *lhe = new TFile("lhe.root", "READ");
  if (!(lhe && lhe->IsOpen())) { delete lhe; return -1; }
  
  TTree *tree;
  lhe->GetObject("tree", tree);
  if (!tree) { delete lhe; return -2; }
  
  tree->SetMakeClass(1); // all branches in decomposed object mode
  tree->SetBranchStatus("*", 0); // disable all branches
  
  Int_t Llep0_ = -1;
  tree->SetBranchStatus("Llep0", 1); // activate "Llep0"
  tree->SetBranchAddress("Llep0", &Llep0_);
  

  Float_t Pt[(_MAX_POSSIBLE_G1XCL_)];
  tree->SetBranchStatus("Llep0.Pt()", 1); // activate "Llep0.Pt"
  tree->SetBranchAddress("Llep0.Pt()", Pt);
  
  Long64_t nevent = tree->GetEntries();
  
  std::cout << "####### nevent = " << nevent << std::endl;
  
  for (Long64_t i = 0; i < nevent; i++) {
    tree->GetEntry(i);
    
    std::cout << "i = " << i << std::endl;
    std::cout << "Llep0_ = " << Llep0_ << std::endl;
    for (Int_t j = 0; j < Llep0_; j++) {
      std::cout << "Pt[" << j <<  "] = " << Pt[j] << std::endl;
    }
  }
  
  tree->ResetBranchAddresses(); // "detach" from local variables
  
  delete lhe; // it will automatically delete "tree", too
  return 0;
}