Two software data organizations that support railroad signaling

One organization supports data in memory; the other supports data in files. Both organizations store data about railroad signal blocks and the way the blocks are organized into lines. A program that uses the organizations was written in the C programming language. The program can create data organizations in memory that represent one or more blocks in a line, save the information in the file organization, read the file back into memory, display a one-line diagram of a block on the computer´s console, or delete the information for a block