Question

Consider the following method.

public static int mystery(int[] arr)
{
int count = 0;
int curr = arr[arr.length - 1];

for (int value : arr)
{
if (value > curr)
{
count = count + 1;
}
else
{
count = count - 1;
}
curr = value;
}

return count;
}
The following code segment appears in another method of the same class.
int[] arr = {4, 14, 15, 3, 14, 18, 19};
System.out.println(mystery(arr));
What is printed as a result of executing the code segment?

A
-7

B
-6

C
3

D
5

E
7

Answer 1

The mystery method iterates through the array, comparing each element to the previous one. If an element is greater, it increments the count; otherwise, it decrements the count. For the given array {4, 14, 15, 3, 14, 18, 19}, the counts are (1, -1, 1, -1, 1, -1), resulting in a final count of -6. Thus, the output is -6. So, the correct option is B -6.

Step-by-step explanation:

The mystery method aims to compute a count based on a comparison between consecutive elements in the provided array. It initializes a count variable to zero and starts by setting the current element (curr) to the last element of the array. Then, it iterates through each element in the array, comparing it to the current element. If the current element is smaller, it increments the count; otherwise, it decrements the count. The current element is then updated for the next iteration.

Applying this logic to the given array {4, 14, 15, 3, 14, 18, 19}, the comparisons proceed as follows: (1, -1, 1, -1, 1, -1). Starting with 0, the count is incremented after the first and third comparisons, and decremented after the second, fourth, and sixth comparisons. The final count is -6, reflecting the net result of these comparisons.

In essence, the method evaluates the directional change between adjacent elements, with positive increments indicating an upward trend and negative decrements signifying a downward trend. For the provided array, the cumulative count illustrates a net decrease, leading to the final answer of -6.