Definition: Patricia Tree that storing every semi-infinite string (sistring) of a document.
You may find what you want on the following web:
www.cse.cuhk.edu.hk/~lyu/student/ mphil/kenny/PATTREE.ppt(English Version)
www.cse.cuhk.edu.hk/~king/PUB/kwok01_isep.pdf (English Version)
Meanwhile,you can search the key worlds "pat+tree"on the internet with google or the like.
BTW:you'd better try to read English discourses and documents if you want to keep out with the latest and all-encompassing knowledge of C++.