Your task is to implement a program in invertedIndex.c that reads data from a given collection of pages in collection.txt and generates an "inverted index" that provides a sorted list $($set$)$ of URLs for every word in a given collection of pages.

One possible $($and recommended$)$ implementation of an inverted index is a binary search tree where each node contains a word and a corresponding file list, which is a linked list. Each node of the file list contains the filename of a file that contains the word. The inverted index tree must be ordered alphabetically $($ascending$)$ by word, and each file list must be sorted alphabetically $($ascending$)$ by filename.

The full inverted index will contain many inverted index nodes arranged in a binary search tree $($ordered alphabetically by word$),$ and each inverted index node will contain a file list. For example: