Given an Iterator class interface with methods:
hasNext(), design and implement a PeekingIterator that support the
peek() operation -- it essentially peek() at the element that will be returned by the next call to next().
Assume that the iterator is initialized to the beginning of the list:
next()gets you 1, the first element in the list. Now you call
peek()and it returns 2, the next element. Calling
next()after that still return 2. You call
next()the final time and it returns 3, the last element. Calling
hasNext()after that should return false.
Follow up: How would you extend your design to be generic and work with all types, not just integer?
Hint 1Think of "looking ahead". You want to cache the next element.
Hint 2Is one variable sufficient? Why or why not?
Hint 3Test your design with call order of