Project 08: Conga!

Objectives¶

1. Practice building List operations.
2. Practice using pointers.
3. Practice test-driven development.

Introduction¶

This week’s project is to complete a program that simulates a Conga Line dance:

Simulation Trace¶

When run, the CongaLine simulation should behave like the trace shown below:

Ann and Bob have started a Conga Line!

 =Ann=Bob

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 1

What is your name? Chris

 =Ann=Bob=Chris

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 2

What is your name? Don
Who do you want to follow? Ann

 =Ann=Don=Bob=Chris

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 2

What is your name? Eve
Who do you want to follow? Bob

 =Ann=Don=Bob=Eve=Chris

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 2

What is your name? Fred
Who do you want to follow? Chris

 =Ann=Don=Bob=Eve=Chris=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 3

What is your name? Gwen
Who do you want to precede? Ann

 =Gwen=Ann=Don=Bob=Eve=Chris=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 3

What is your name? Hal9000
Who do you want to precede? Eve

 =Gwen=Ann=Don=Bob=Hal9000=Eve=Chris=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 3

What is your name? Ivy
Who do you want to precede? Fred

 =Gwen=Ann=Don=Bob=Hal9000=Eve=Chris=Ivy=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 2

What is your name? Joe
Who do you want to follow? Bilbo

*** Bilbo is not dancing!

 =Gwen=Ann=Don=Bob=Hal9000=Eve=Chris=Ivy=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 3

What is your name? Jon
Who do you want to precede? Frodo

*** Frodo is not dancing!

 =Gwen=Ann=Don=Bob=Hal9000=Eve=Chris=Ivy=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 0

*** 0 is not a valid choice!


 =Gwen=Ann=Don=Bob=Hal9000=Eve=Chris=Ivy=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 5

*** 5 is not a valid choice!


 =Gwen=Ann=Don=Bob=Hal9000=Eve=Chris=Ivy=Fred

Conga, Conga, Con-GA!  Conga, Conga, Con-GA!

Please enter:
 1 to join the Conga line at the end
 2 to join the Conga line after a particular person
 3 to join the Conga line before a particular person
 4 to quit
--> 4

Details¶

Accept the project assignment and use git clone to get the files.

The CongaLine class in CongaLine.h has a List member named myLine, in which it stores the names of the people currently in the dance line. Since a Conga Line needs to have at least two people, the CongaLine constructor has two string parameters to which we can pass two people’s names, and our simulation uses this constructor to create an initial line containing “Ann” and “Bob”.

Assuming your List template is correct, these files should build (make tester and make proj8) and run correctly as they are. However, some of the lines in the file CongaLine.cpp are “commented out”, including:

//  if (!myLine.insertAfter(otherPersonsName, yourName)) {
//      cout << "\n***" << otherPersonsName
//           << " is not dancing!\n" << endl;
//  }

and

//  if (!myLine.insertBefore(otherPersonsName, yourName)) {
//      cout << "\n***" << otherPersonsName
//           << " is not dancing!\n" << endl;
//  }

and

//  cout << "\n " << myLine << "\n\n";

Before you can uncomment these lines, you will need to implement the corresponding List operations in List.h.

The insertBefore/After Methods¶

The semantics of the first two operations are as follows:

• myLine.insertAfter(otherPersonsName, yourName); Assuming that otherPersonsName is present in myLine, this operation should insert yourName into myLine immediately after otherPersonsName.
• myLine.insertBefore(otherPersonsName, yourName); Assuming that otherPersonsName is present in myLine, this operation should insert yourName into myLine immediately before otherPersonsName.

Each operation should work correctly regardless of the position of otherPersonsName within myLine. If otherPersonsName is present within myLine, your operation should return true; otherwise it should return false, so that CongaLine::run() can display an error message.

The Output operation¶

The semantics of the third operation are as follows:

anyOstream << myLine << ...

This << operation should insert the items in myLine into the ostream that is its left operand, with each item preceded by an “=” separator-string. (The lines in the = character represent a person’s arms.)

This operation should return a reference to its left operand, so that these operators can be chained.

Miscellaneous¶

You should use test-driven development to implement these operations. A part of your grade will be based on the thoroughness of your tests. Add your tests to the provided tests.cpp.

For the insert operations, I strongly encourage you to “design” your method by drawing a diagram of what you want to have happen to the structure in each case. Once you have a diagram to go by, you are more likely to write code that actually does the right thing. (Trial and error is not a good debugging technique.)

If you get to the point where you cannot figure out what is wrong, use the debugger! The debugger is the best way to debug problems with pointers!

And finally, here is a silly video, in case you need some inspiration.

Submit¶

Make sure you commit your changes and push them to the online repository.

Grading Rubric¶

The project is worth 25 pts:

• satisfies all requirements: 3 pts
• insertAfter() test: 3 pts
• insertAfter() method: 3 pts
• insertAfter() efficiency: 1 pt
• insertBefore() test: 3 pts
• insertBefore() method: 3 pts
• insertBefore() efficiency: 1 pt
• operator<<() test: 3 pts
• operator<< function: 3 pts
• Style/Documentation: 2 pts

Ways students lost points in the past:

• -2: insertAfter and insertBefore goes through entire list, even after finding targetNode
• -4: insertAfter and insertBefore tests are not sufficient: did not test inserting that fails, explicitly checking node values, etc
• -18: 's, 's, 's, and 's List.h differs only in indentation
• -25: does not compile. Nothing seems to have been implemented
• -3: program crashes when try to insert before a person that is not in the list.
• -1: crashes when insert before first person
• -1: poor indentation! So easy to fix...
• -5: tests do not pass -- cause crash
• -1: insert function(s) do not increment size
• -5: program does not display the Conga Line after changes: impossible to test
• -2: insert functions go through the list twice each
• -2: no tests for << operator
• -2: tests do not test failed insertions
• -3: New people are inserted twice each time
• -1: failed insertions are not communicated to the user
• -9: no tests
• -2: test cases are insufficient: 1 (or 2) successful call to each function is enough to test all cases?
• -3: infinite loop when insert in beginning of list.