Data Structures and Algorithms in Java[1].pdf - Fulvio Frisone

time. However, methods addFirst and removeFirst of the deque each run
in O(n) time.
Actually, with a little effort, we can produce an array-based implementation of the
array list ADT that achieves O(1) time for insertions and removals at index 0, as
well as insertions and removals at the end of the array list. Achieving this requires
that we give up on our rule that an element at index i is stored in the array at index
i, however, as we would have to use a circular array approach like the one we
used in Section 5.2 to implement a queue. We leave the details of this
implementation for an exercise (C-6.9).
6.1.4 A Simple Interface and the java. util. ArrayList Class
To prepare for constructing a Java implementation of the array list ADT, we show,
in Code Fragment 6.2, a Java interface, IndexList, that captures the main
methods from the array list ADT. In this case, we use a
IndexOutOfBoundsException to signal an invalid index argument.
Code Fragment 6.2:
the array list ADT.
The IndexList interface for
The java.util.ArrayList Class
Java provides a class, java.util.ArrayList, that implements all the
methods that we give above for our array list ADT. That is, it includes all of the
methods included in Code Fragment 6.2 for the IndexList interface.
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