Task 1: "Group Anagrams

You are given an array of strings @S.

Write a script to group sets of Anagrams (containing the same letters), the order of the anagram-sets doesn't matter.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1:

    Input: ("opt", "bat", "saw", "tab", "pot", "top", "was")
    Output: [ ("bat", "tab"),
              ("saw", "was"),
              ("top", "pot", "opt") ]

Example 2:

    Input: ("x")
    Output: [ ("x") ]
"

My notes: yippee!  Good old "Programming Pearls" by Jon Bentley tackled a very similar problem, using SIGNATURES (the sorted bag of letters
contained in a word) - all anagrams with the same signature form part of the same anagram group.  Ideal data structure time:

"if only we could have a data structure mapping from a signature to a list of all the words with that signature".

Ok, let's build that then: a HoA.


Task 2: "Binary Tree to Linked List

You are given a binary tree.

Write a script to represent the given binary tree as an object and flatten it to a linked list object. Finally print the linked list object.

Example:

    Input:

        1
       / \
      2   3
     / \
    4   5
       / \
      6   7

    Output:

        1 -> 2 -> 4 -> 5 -> 6 -> 7 -> 3
"

My notes: again with the binary trees - no notes on representation, so I'll reuse the one I've used before.
I think the "flatten to a linked list object" means "perform a pre-order traversal producing a list".