I think the simplest method is to put the AREAS into a String, Set HashMap, then enter all the associated CODES into the relevant map. Then, you can get the Set of all codes for an area or iterate over the sets to find which one contains the code you are searching for.
Check out the guava multimap. I believe it provides the functionality you want.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.