#include "TGraph.h"
#include "TFile.h"

void root_problem()
{
	double x[] = {0, 1, 2, 3};
	double y[] = {0, 1, 4, 9};
	TGraph *g = new TGraph(4, x, y);

	const char dirName[] = "first>second";
	const char objName[] = "g";
	char path[100];
	sprintf(path, "%s/%s", dirName, objName);

	TFile *f = new TFile("root_problem.root", "recreate");
	gDirectory = f->mkdir(dirName);
	g->Write(objName);
	delete f;

	f = new TFile("root_problem.root");
	g = (TGraph *) f->Get(path);
	printf("g = %p\n", g);	// -> NULL

	TDirectory *d = (TDirectory *) f->Get(dirName);
	g = (TGraph *) d->Get(objName);
	printf("g = %p\n", g);	// -> OK

	delete f;
}