Assignment #3: Implementing a retrieval system for supporting spelling errors 

1,Support spelling correction with Levenshtain distance.

Run by: 

make                  #create myindex and mysearch

./myindex	          #The index has been built. If you want to build again, run this!
                       You must put docs in ./input/doc_data/, and build the index,
                       
./mysearch < query    # Search for the given query. Proximity query : the default distance of two terms £º10 letters£¬
						you can modify it in ./util/util.h : #define K 10