add disjoint_set
Merge pull request #10 from wyh267/master

add LRU cache algorithm
Merge pull request #11 from wyh267/master

fix bugs in base64.h
update base64 for code formatting
update readme
Update LRU_cache.h
Merge pull request #12 from wyh267/patch-1

Update LRU_cache.h
update README.md
format LRU_cache
update comment for random_select
Merge branch 'master' of https://github.com/xtaci/algorithms
update random_select.h
update readme.md
Merge branch 'master' of https://github.com/xtaci/algorithms
add max subarray problem
update README.md
update queue.count method
add capcity method for queue
rename skiplist, enhance error process
refactoring bst