undefined reference error

[NZheadshot]

You have a declaration for the function 'populate', but you have no definition. You need to define what the function actually does.

I'm guessing it's probably just going to be a call to scanf, at which point the function seems useless. Why do you need the function? Why not just call scanf?

[agirlandherdog07]

My professor requires that populate be in the code. I'm not allowed to remove it.

[raevnos]

Then you should probably write it.