Trie Solution                                       Carol Zander (CSS 343)
-------------

1. Build a trie with the following words:
pan pant pane pain paint painter

Array elements showing nothing inside actually have nullptr in them.
An  X  in the last position means the pointer is not nullptr,
that the word is in the dictionary.

     a  b  c  d  e          p        z  $
    +--+--+--+--+--+------+---+-----+--+--+
 -->|  |  |  |  |  | ...  |   | ... |  |  |
    +--+--+--+--+--+------+-/-+-----+--+--+
                           /
                +---------+
                |     a    
                |   +---+--+--+--+--+---------------+--+--+
                +-->|   |  |  |  |  |       ...     |  |  |
                    +-/-+--+--+--+--+---------------+--+--+
                     /
                +---+ 
                |             i           n
                |   +-------+---+-------+---+--------+--+
                +-->| ...   |   |  ...  |   | ...    |  |
                    +-------+-/-+-------+-/-+--------+--+
                             /           /
 +--------------------------+       +---+                             
 |                n                 |           e           t         
 |   +----------+---+--------+--+   |   +-----+---+-------+---+-----+---+  
 +-->|     ...  |   | ...    |  |   +-->| ... |   |  ...  |   | ... | X |
     +----------+-/-+--------+--+       +-----+-/-+-------+-/-+-----+---+ 
                 /                             /           /          
+---------------+            +----------------+     +-----+           
|             t              |                      |            
|   +-------+---+---+---+    |   +---------+---+    |   +---------+---+   
+-->|  ...  |   |...| X |    +-->|   ...   | X |    +-->|   ...   | X |
    +-------+-/-+---+---+        +---------+---+        +---------+---+
             /                                      
            /  
  +--------+    
  |             e   
  |   +-------+---+---+---+ 
  +-->|  ...  |   |...| X | 
      +-------+-/-+---+---+
               /                                      
              /  
     +-------+    
     |               r   
     |   +---------+---+-----+--+ 
     +-->|   ...   |   | ... |  | 
         +---------+-/-+-----+--+
                    /
                   /
     +------------+    
     |            
     |   +------------------+---+ 
     +-->|       ...        | X | 
         +------------------+---+