A A A


B A T


C A B


*B*


From the root, search for B*.

   B does match BAT, so starting from B I'll search for *.

   From B, I search for  ""

     I don't find "" since my B is not at the end of string.

   And from A I search for *.

      From A I search for "".

        I don't find "" since A is not at the end of the string.

      From T I search for *.

         From T I search for "".

            T is the end-of-string, so I found it, BAT gets printed.

From all of my children, search for *B*.

  From A, search for *B*

    From (the first) A, I search for B*

      This fails, since I have no B child.

    From (the second) A, I search for *B*

      From (the second) A, I search for B*.

         This fails, since this A has no B child.

      From (the third) A, I search for *B*.

        From (the third) A, I search for B*.

          This fails, since this has no B child.

    From C I search for B*

      This one fails, since C has no B child.

    From A I search for *B*.


      From A I search for B*.

         Since I have a B child, from B I search for *.

            From B, I search for "".

               Since B has an end-of-string marker, I find "" I print "CAB".

      From B I search for *B*.

         From B, I search for B*.

            B has no B child, so this search fails.



In Java, int is not a class, and so you can't use them in HashMaps

BUT...

Integer IS totally a class.  Integer is a wrapper class for int.