Module 6 Homework
Cyclomatic Complexity

10 points

Building a Flow Graph and Calculating Cyclomatic Complexity, V(G)
When you are doing white box testing, I am a strong proponent of doing cyclomatic complexity calculations and basis path testing, provided you have the time to do so. Since it guarantees complete statement and branch coverage, basis path testing gives you an absolute minimum number of test cases you should run for any given code fragment. This homework is an exercise in constructing a flow graph and calculating the cyclomatic complexity of a code fragment.

What you need to do:
For the code fragment shown below, do the following:

Construct a flow graph for the code.  You may do this in any way that allows you to send it to me in digital format.  You can create the graph using Visio, Word, or some other application.  You can also draw it on paper and scan it in – just make sure it’s clearly readable.

From your flow graph, calculate the cyclomatic complexity, V(G), using all three of the methods discussed in class.  All three calculations should agree with each other.
The code is written in Java, so you are all probably familiar with the syntax to some extent. In the event you are unable to follow the syntax, please let me know. You needn’t be concerned with what the code itself is supposed to do.

private void downShift(int index)
{
    // index of “child”, which will be either index * 2 or index * 2 + 1
    int childIndex;

    // temp storage for item at index where shifting begins
    Comparable temp = theItems[index];

    // shift items, as needed
    while (index * 2 <= theSize)
    {
        // set childIndex to “left” child
        childIndex = index * 2;

        // move to “right” child if “right” child < “left” child
        if (childIndex != theSize && theItems[childIndex + 1].compareTo(theItems[childIndex]) < 0)
            childIndex++;

        if (theItems[childIndex].compareTo(temp) < 0)
        {
        // shift “child” down if child < temp
            theItems[index] = theItems[childIndex];
        }
        else
        {
            // shifting complete
            break;
        }

        // increment index
        index = childIndex;
    }

    // position item that was originally at index where shifting began
    theItems[index] = temp;
}

What you need to turn in:
Your flow graph in one of the following formats:

Visio document (.vsd)

Word or Rich Text document (.doc, .rtf)

JPEG or GIF image (.jpg, .gif)

Your 3 V(G) calculations.