Software Testing

POTD 10: Data flow graph coverage — LCM

Due 4-June-2026, 11:59pm EST

Purpose: Purpose:

Create graph representation for source code
Understand Defs, Uses, DU-pairs, DU-paths
Apply data flow graph coverage to source code
Get ready for the learning portfolio

You may make a copy of a worksheet and complete this activity, or simply type your answers in any text editor.

You may work alone or with another student in this course.

Consider the following Java method

// Calculate_LCM takes two numbers and 
// return LCM (Lease Common Multiplier) of the two numbers
// Examples: 
//    LCM of 12 and 15 = 2 * 2 * 3 * 5 = 60
//    LCM of 12 and 18 = 2 * 2 * 3 * 3 = 36
//    LCM of 15 and 18 = 2 * 3 * 3 * 5 = 90

public static int Calculate_LCM(int n1, int n2)
{
    int result = 1;
    int i = 2;
    if (n1 > n2)
        result = n1;
    else 
        result = n2;
	
    int temp = result;
    while (result % n1 != 0 || result % n2 != 0)
    {
        result = temp * i;
        i++;
    }
      
    return result;
}

Annotate the following Control Flow Graph for the Calculate_LCM method with defs and uses. Alternatively, you may draw a Control Flow Graph from scratch and then annotate the graph with all information (code on nodes, code on edges, defs, and uses).
List all du-pairs, then derive du-paths (the du-paths then can be used as test requirements)

Variables DU-pairs DU-paths

Apply All-Defs coverage to design tests

Variables	Test requirements (DU-paths)	Test paths	Test cases (input values and expected output)

Apply All-Uses coverage to design tests

Variables	Test requirements (DU-paths)	Test paths	Test cases (input values and expected output)

Apply All-DU-Paths coverage to design tests

Variables	Test requirements (DU-paths)	Test paths	Test cases (input values and expected output)

Grading rubric

[Total: 10 points]: Done (or provide evidence of your attempt, full or reasonable effort)

(5 points) — Providing evidence of your attempt, minimal effort

(-2.5 points) for 24 hours late (submitted after 4-June-2026 11:59pm EST, by 5-June-2026 11:59pm EST)
(-5 points) for 48 hours late (submitted after 5-June-2026 11:59pm EST, by 6-June-2026 11:59pm EST)

Submission

For this POTD, you may draw a graph on paper or an electronic device. Then, take a picture or screenshot of your graph and embed it in your report.
Save your POTD as a .pdf file — No Word document.
Upload your POTD to POTD 10 on Gradescope.
Make sure you connect your partner to your group on Gradescope so that everyone receives credit
Each team submits only one copy

Making your submission available to instructor and course staff is your responsibility; if we cannot access or open your file, you will not get credit. Be sure to test access to your file before the due date.

CC-BY-NC-SA 4.0 license.
Last updated 2026-05-31 12:57

Variables	DU-pairs	DU-paths