[ndnSIM] error: program 'ndn-simple' not found; available programs are: ...

[Amin Karami]

Hi,
(1)
When i want to run simulation scenarios from ndnSIM folder (in examples/ 
folder suc as ndn-simple.cc), i face with this error:
program 'ndn-simple' not found; available programs are: 
['scratch-simulator', 'scratch/scratch-simulator', 'subdir', 
'scratch/subdir/subdir', 'test-runner', 'utils/test-runner', 
'bench-simulator', 'utils/bench-simulator', 'bench-packets', 
'utils/bench-packets', 'print-introspected-doxygen', 
'utils/print-introspected-doxygen', 'emu-sock-creator', 
'src/emu/emu-sock-creator', 'tap-device-creator', 
'src/fd-net-device/tap-device-creator', 'raw-sock-creator', 
'src/fd-net-device/raw-sock-creator', 'tap-creator', 
'src/tap-bridge/tap-creator']

But, i can run .cc scenarios files from NS-3 folder (in scratch/ folder) 
successfully.
What is wrong here?
(2)
Also, when i run "./waf" with any option, it needs 'sudo'. What is wrong?

/Amin