DFT in C++

[EngVanya]

Hi guys,
I need some help to convert a signal from time domain (i.e. a sampled waveform) and perform a DFT on it in frequency domain to see its amplitude spectrum using C++.
The number of samples must be within the range 8 to 1000 and needs to be stored in a real array x[1000].
Could you please help me writhe the c program code for this task? Please.
Thanks everyone.

 

[EngVanya]

By the way guys. I would like to know as well how do I print the output of the signal for:
A Sinusoid
A Squarewave
A waveform consisting of the addition of 3 sinusoids

Thanks once again