After implementing this substring search tool using the TrieST class, you should have noticed 
that this isn't a particularly efficient way to go about solving the problem: there's a lot of 
wasted space in the data structure, and a lot of wasted calculation in the search step. 

- Please describe the approach you've used. What is the run time in terms of the size of S, 
and in terms of the length of each q?  I recommend testing (doing experiments!) with some 
large strings, for confirmation. 

- What approaches could you take to improve on this clever idea?


ANSWER: