To better model a FIFO queue in which entries may be deleted before reaching the front, design a PositionalQueue class that supports the complete queue ADT, yet with enqueue returning a position...

To better model a FIFO queue in which entries may be deleted before

reaching the front, design a PositionalQueue class that supports the complete

queue ADT, yet with enqueue returning a position instance and support

for a new method, delete(p), that removes the element associated

with position
p
from the queue. You may use the adapter design pattern

(Section 6.1.2), using a PositionalList as your storage.