Lines 176-187 in Farm.h are probably never reached and could be removed. Need to verify this before removal.

Removing the calls to std::cout from display_farm() in Farm.h would allow the removal of <iostream>. This would need to be done by having display_farm() return a multiline string and rewrite any calls to display_farm() (which I think there are none) to handle and display the string.

This probably also means renaming the function. (get_farm_as_string? get_farm_viz?)

Removing the call to std::sort() from get_fertile_area() in Farm.h would allow the complete removal of <algorithm>.

Adding a fertile area private variable and updating it with each time field is touched by fill_cell() would allow the removal of the section in get_fertile_area() that counts it up after the fact.

The current string parsing is out of alignment with the spec. For example,

{"4 0", "7",} 9 

should not be interpreted correctly as "4 0 7 9." This has been nice for testing, and allows for things like:

48 192 351 207 48 392 351 407 120 52 135 547 260 52 275 547

to actually run, but that is technically out of spec.