PLAYER0 is the human player
PLAYER1 is the computer (smart)
  1. starts with the current word string
  2. searches dictionary to find all the possible words extending from
     this current word string, puts these into a list
  3. randomly chooses one of these next possible words from this list
  4. picks the next letter from this new word chosen from the list
  5. also checks for possible challenge conditions:
     - if word string is a word in the dictionary 
     - if there are no words that can extend from word string
     returns "!" as the new letter, to signify a challenge
  

ruby ghost02.rb
numplayers= 2
New word to pick

Player 0 pick a letter  (HUMAN)
Current word=, Letter?
a
Current word: ["a"], string: a

Player 1 pick a letter   (COMPUTER)
Computer adding to a
Current word: ["a", "l"], string: al

Player 0 pick a letter  (HUMAN)
Current word=al, Letter?
b
Current word: ["a", "l", "b"], string: alb

Player 1 pick a letter   (COMPUTER)
Computer adding to alb
Current word: ["a", "l", "b", "u"], string: albu

Player 0 pick a letter   (HUMAN)
Current word=albu, Letter?
m
Current word: ["a", "l", "b", "u", "m"], string: album
album found at position 1128

Player 1 pick a letter  (COMPUTER)
Current word: album
album found at position 1128, return "!"
Challenge issued, player 0 has ["G"], all players: [["G"], []]
THE HUMAN HAS 1 LETTER: "G"


New word to pick
Player 0 pick a letter   (HUMAN)
Current word=, Letter?
a
Current word: ["a"], string: a

Player 1 pick a letter   (COMPUTER)
Computer adding to a
Current word: ["a", "s"], string: as
as found at position 2381   (THIS IS A WORD, BUT NOT 4 LETTERS LONG)

Player 0 pick a letter    (HUMAN)
Current word=as, Letter?
p
Current word: ["a", "s", "p"], string: asp
asp found at position 2433    (THIS IS A WORD, BUT NOT 4 LETTERS LONG)
Player 1 pick a letter    (COMPUTER)
Computer adding to asp
Current word: ["a", "s", "p", "i"], string: aspi

Player 0 pick a letter   (HUMAN)
Current word=aspi, Letter?
r
Current word: ["a", "s", "p", "i", "r"], string: aspir

Player 1 pick a letter   (COMPUTER)
Computer adding to aspir
Current word: ["a", "s", "p", "i", "r", "a"], string: aspira
aspira not found

Player 0 pick a letter     (HUMAN)
Current word=aspira, Letter?
t
Current word: ["a", "s", "p", "i", "r", "a", "t"], string: aspirat
aspirat not found

Player 1 pick a letter    (COMPUTER)
Computer adding to aspirat
Current word: ["a", "s", "p", "i", "r", "a", "t", "i"], string: aspirati
aspirati not found

Player 0 pick a letter    (HUMAN)
Current word=aspirati, Letter?
o
Current word: ["a", "s", "p", "i", "r", "a", "t", "i", "o"], string: aspiratio
aspiratio not found

Player 1 pick a letter     (COMPUTER)
Computer adding to aspiratio
Current word: ["a", "s", "p", "i", "r", "a", "t", "i", "o", "n"], string: aspira
tion
aspiration found at position 2449

Player 0 pick a letter    (HUMAN - CHALLENGE WITH "!")
Current word=aspiration, Letter?
!
Current word: aspiration
aspiration found at position 2449

Challenge issued, player 1 has ["G"], all players: [["G"], ["G"]]

NOW BOTH PLAYERS HAVE 1 LETTER, "G"

New word to pick
Player 1 pick a letter    (COMPUTER)
Computer adding to
Current word: ["a"], string: a
a not found

Player 0 pick a letter    (HUMAN)
Current word=a, Letter?

...