Question

A list of numbers is considered increasing if each value after the first is greater than or equal to the preceding value. The following procedure is intended to return true if numberList is increasing and return false otherwise. Assume that numberList contains at least two elements.
Line 1:  PROCEDURE isIncreasing(numberList)
Line 2:  {
Line 3:     count 2
Line 4:     REPEAT UNTIL(count > LENGTH(numberList))
Line 5:     {
Line 6:        IF(numberList[count] < numberList[count - 1])
Line 7:        {
Line 8:           RETURN(true)
Line 9:        }
Line 10:       count count + 1
Line 11:    }
Line 12:    RETURN(false)
Line 13: }

Question
14

Mark for Review

Which of the following changes is needed for the program to work as intended?

In line 3, 2 should be changed to 1.
Option A,In line 3,  2  should be changed to  1 .

In line 6, < should be changed to ≥.
Option B,In line 6,  <  should be changed to  ≥ .

Lines 8 and 12 should be interchanged.
Option C,Lines 8 and 12 should be interchanged.

Lines 10 and 11 should be interchanged.

Answer 1

To determine the necessary change for the procedure to correctly return true if the `numberList` is increasing, we must analyze the logic of the code.

1. **Line 3**: The initial value of `count` is set to 2, which is appropriate since the procedure compares the current element in the list (at index `count`) with the previous element (at index `count - 1`). Starting from count 2 allows it to correctly compare the second element with the first element.

2. **Line 6**: This line checks if the current element is less than the previous one (`numberList[count] < numberList[count - 1]`). For a list to be increasing, each element should be greater than or equal to the previous one. Therefore, this condition should use the comparison operator `≥` instead of `<`, so that it detects the non-increasing case correctly.

3. **Lines 8 and 12**: The logic here is inverted. The procedure should return `false` when it finds that the list is not increasing, and it should return `true` only if it makes it through all checks without finding a violation. The current structure would incorrectly return true when a decrease is found, and falsely return false at the end.

4. **Lines 10 and 11**: The order of these lines is correct. The counter is incremented before the next iteration condition is checked.

Based on the analysis, the necessary change to make the procedure work as intended is:

**Option B:** In line 6, `<` should be changed to `≥`.

After this change, the procedure will correctly check for the increasing nature of the list and return true or false accordingly.