VS 2012: N00bie - Reading/writing an array from txt file?

New to all this so bear with me. Haven't done any serious programming since the days of the spectrum zx81.

I have a file "numbers.txt" which looks like this...

0 1 4
2 6 3

I want to read this file into my app as...

a(0)=0, a(1)=1... a(5)=3

Also how would I do the reverse. i.e. write an array to file?

Thanks