The following procedure is intended to return the number of times the value val appears in the list myList. The procedure does not work as intended.
Line 01: PROCEDURE countNumOccurrences(myList, val)
Line 02: {
Line 03: FOR EACH item IN myList
Line 04: {
Line 05: count ← 0
Line 06: IF (item = val)
Line 07: {
Line 08: count ← count + 1
Line 09: }
Line 10: }
Line 11: RETURN(count)
Line 12: }
Which of the following changes can be made so that the procedure will work as intended?
Correct Answer: ?????
This problem is testing your understanding of how to fix a simple algorithm so that it correctly counts how many times a given value (val) appears in a list (myList).
The algorithm has the goal of looping through every item in the list and checking if the item matches the value val. If it does, it should increase the count by 1.
However, there's a problem with where the variable count is set to 0. It’s currently set inside the loop, which means count resets to 0 every time it checks a new item. This means the algorithm will only ever count at most 1 occurrence.
By moving the count = 0 line before the loop, the algorithm will initialize count to 0 once at the start, and then it will properly add 1 each time it finds val in myList. This allows the procedure to correctly accumulate the total number of times val appears.
Key Takeaway: When you're writing loops that accumulate a result, make sure your accumulator (in this case, count) is initialized outside of the loop. That way, it doesn't reset every time the loop runs.