We are now ready for the last piece:
 - compute the counts of  values that appear in a particular input file

And then to put all the pieces together.  Before you start, notice that
we have placed symlinks (short for "symbolic links") to the files you worked on
in the previous problems.  Symbolic links basically mean that when you open
the file, it will open the file it links to (so opening counts.c will open
../27_counts/counts.c ).  

For this problem, you will start by writing the function:

  counts_t * countFile(const char * filename, kvarray_t * kvPairs)

in the main.c file. Note that you will find it quite helpful to use several of the functions
you wrote in the previous problems (in fact, much of the work should already be done).

Once you have written countFile, it is time to write your main function.  You 
will also write this function in the main.c file. Note that we have already
written the high-level algorithm for the main function as comments, so you can
just translate this algorithm to code.  You will also need to add some error
checking. 

Once you finish writing these two functions, you should have a working program!
Compile, test, and debug it.

We have provided two test cases, and the correct output for them.

The first test case:
  ./count_values kvs1.txt list1a.txt list1b.txt

should produce two output files (list1a.txt.counts and list1b.txt.counts).
The correct contents can be found in list1a.txt.ans and list1b.txt.ans.

The second test case:
  ./count_values kvs2.txt list2a.txt list2b.txt list2c.txt

should produce 3 files (named appropriately) and the answers can be found in
similarly named .ans files.

Use git add . to submit your work.