Implement a contains method that operates in less than O(n) time.

http://faculty.edcc.edu/paul.bladek/CS132/p2.htm

This numerical puzzle originates from the Turkish Intelligence Foundation sent to Will Shortz by Turkish puzzler Metin Orsel. Start with a certain number on a telephone keypad. Move to another number adjacent to it horizontally, vertically or diagonally. Then move to another number adjacent to that one horizontally, vertically or diagonally. And keep doing this until you have 9 digits. All the digits must be different. That is, you'll use 9 of the 10 digits on the phone including zero (0) and the path must not cross itself. When you're done, the number formed by the first 3 digits plus the number formed by the next 3 digits will equal the/ number formed by the last 3 digits. There's only one path that reaches this solution. What is it?
1++2++3
4++5++6
7++8++9
+++0+++
It turns out that there are actually two correct solutions. If you did not have the restriction of no crossed paths, there would be three solutions.

Given an Array of Arrays, return true/false if a given word exists within the "soup".

Directions that should be allowed
Left->Right
Top->Bottom
UpperLeft->LowerRight

Search word can be smaller than total height/length of array.

find "hello" below

a b h f k
w z e c s
h e l w o
u f l n m
o y o h h

Given a sequence of numbers, defined as the PreOrder, InOrder, and/or PostOrder traversal of a binary tree. Recreate the tree.

Example:
PreOrder 7,10,4,3,1,2,8,11
InOrder 4,10,3,1,7,11,8,2

Resulting Binary Tree:

                             ---- 7 ----
                         /                 \
                      10                    2
                     /   \                /
                    4     3              8
                             \          /
                               1       11

Traversal Definitions Here:
http://en.wikipedia.org/wiki/Tree_traversal