Data Structure

What is the best data structure for NOTEPAD and WORD PROCESSOR

Just for the information...this was asked in trilogy's exam

I humbly suggest you elaborate on your question.

1. Best data structure for which part of Notepad/Word? The user interface? Or the character buffer? If it is the latter, catch22 has some tutorials on memory management for large-file editors.

2. What is the Trilogy exam? I tried searching Google for it, but couldn't find it.

here is the link to the company site (http://www.trilogy.com)

I found this company's exam in placement papers site...there was no other details given in the question