Algorithms: Tree traversal, Depth-first-search (DFS), Breadth-first-search (BFS)

http://en.wikipedia.org/wiki/Depth-first_search
http://en.wikipedia.org/wiki/Tree_traversal
http://en.wikipedia.org/wiki/Iterative_deepening_depth-first_search

Q: how to invert binary tree?
DO:  pascal triangle problems
DO: cases using stacks
DO:Graph algs
LRN: Quick sort, insert sort, bobble sort, selection sort, binary tree search
graph search.