COEN 79L - Lab 3 § Sequence

COEN 79L - Object-Oriented Programming and Advanced Data Structures
Lab 3
§ Sequence
A sequence class is similar to a bag—both contain a bunch of items, but unlike a
bag, the items in a sequence are arranged in an order. In contrast to the bag
class, the member functions of a sequence will allow a program to step
through the sequence one item at a time. Member functions also permit a
program to control precisely where items are inserted and removed within
the sequence.
Our sequence is a class that depends on an underlying value_type, and the class
also provides a size_type.
Three member functions work together to enforce the in-order retrieval rule:
void start( );
value_type current( ) const;
void advance( );
§ After activating start, the current function returns the first item
§ Each time we call advance, the current function changes so that it returns the
next item in the sequence
Provide some additional useful member functions, such as:
1. insert_front: insert a new value at the front of the sequence. This new item
should now be the current item.
2. remove_front: remove the value at the front of the sequence. The new front
item should now be the current item.
3. attach_back: insert a new value at the back of the sequence. This new item
should now be the current item.
4. end: The last item in the sequence should now be the current item.
5. operator+ and operator+=: These operators should have the precondition
that the sum of the sizes of the two sequences being added is smaller than
the CAPACITY of a sequence.
Subscript operator:
For a sequence x, we would like to be able to refer to the individual items using the
usual C++ notation for arrays. For example, if x has three items, then we want to be
able to write x[0], x[1], and x[2] to access these three items. This use of the
square brackets is called the subscript operator. The subscript operator may be
overloaded as a member function, with the prototype shown here as part of the
sequence class:
COEN 79L - Object-Oriented Programming and Advanced Data Structures
Lab 3
class sequence {
public:
...
value_type operator [] (size_type index) const;
...
As you can see, the operator[] is a member function with one parameter. The
parameter is the index of the item that we want to retrieve. The implementation of
this member function should check that the index is a valid index (i.e., index is less
than the sequence size), and then return the specified item.
For this project, specify, design, and implement this new subscript operator for the
sequence.
More information about the sequence class is available in Slide Set 3.
à The documentation of the sequence class has been provided for you in
the sequence1.h file.
• Make sure you include the invariants of the class on top of the implementation
(*.cpp) file.
Submission Guideline
The names of the files that you submit should be sequence1.h and
sequence1.cpp. When you upload your solution to Camino, please make sure that
your sequence is set up to hold the value_type of double and has a capacity of
50.
Test your program using the official_seq_tes.cpp code provided.