to compile:

rm -f writeHist
rm -f  readHist
c++ -Wall `root-config --cflags --libs` -o writeHist writeHist.cc
c++ -Wall `root-config --cflags --libs` -o  readHist  readHist.cc

or

source compile

------------

to run:

writeHist hh.root
readHist  hh.root

