Informal Code Analysis

Learning objective: Compute statement execution counts & informal run-time comparison of iterative statements

Essential Knowledge: A statement execution count indicates the number of times a statement is executed by the program

What IS informal code analysis?

Answer:

// CODE EXAMPLE #1 (for loop)
public class InformalCodeAnalysis {
    public static void main(String[] args) {
        int count = 0;
        for (int k = 0; k < 30; k++)
        {
            if (k % 3 == 0) // statement 1
            {
                count++; // statement 2
            }
        }
    }
}

How many times will statement 1 execute?

Answer:

How many times will statement 2 execute?

Answer:

<b>How many times will statement 3 execute?</b>

Answer:

// Rewrite the code segment below to have a faster run-time based on statement execution counts
for (int k = 0; k < 135; k++)
{
    if (k % 5 == 0)
    {
        System.out.println(k);
    }
}

// CODE EXAMPLE #3 (while loop)

int num = (int)(Math.random() * 10);
while (num % 2 != 0)
{
    num = (int)(Math.random() * 10) // statement 4
}

<b>What is the min/max number of times statement 4 will execute?</b>

Answer:

// CODE EXAMPLE #4 (nested loop)

for (int outer = 0; outer < 3; outer++)
{
    for (int inner = 0; inner < 4; inner++)
    {
        // statement #5
    }
}