Write a program to implement the inverted file shown in the slides (Simple Index file, LabelID file and Data file).  Use the Avail_List to point at the deleted Label IDs so that their spaces can be re-used for new records.  Insert the example data in the slides in the three files (see below).

Data file: 

Simple Index: 

LabelID file: 

Then, show the content of the files and the Avail_List after each of the operation:Add a new data record with a new composer name "Xxxx"and new label ID "XXX12345".Add a new data record with a new composer name "Bbbbb"and new label ID "BBB12345".Delete data record with key "DG139201".Delete data record with key "COL31809"Add a new data record with a new composer name "Hhhhh"and new label ID "HHH12345".

Draw a B-tree and show its content after every operation.  The nodes in the B-tree can store maximum of 4 keys and minimum 2 keys.  
Insert: A,G,F,B,K,D,H,M,Insert: J,Delete: A, D,Insert: E,S,I,R,X,Delete: M,Insert: A,C,D, Delete: S,Insert: L,N,T,U,Delete: R