added stuff from lecture notes
Merge branch 'master' into crappy
editted intro
removes punctuations
done with queues and stacks chapter (for now)
implements stack&queue using linked lists
changed code font size
updated figures in pq chapter
updated tree chapter
added sorting chapter with insertion, quick, bucket sorting algos
added hashing chapter
added algo tech chapted
added content to union find
added short preface
started random chapter
added randomized quick sort
done with hashing
updated figures in graph chapter
updated bfs fig
added greedy to algo chapter