How many calls to mystery are made (including the first call) of mystery(0, 4, 5) when arr = {1, 2, 3, 5, 7}?

Question

Give the following code:

private int[] arr;
public int mystery(int low, int high, int num) {
int mid = (low+high) / 2;
if (low > high) {
return -1;
}
else if (arr[mid] < num) {
return mystery(mid +1, high, num);
}
else if (arr[mid] > num) {
return mystery(low, mid - 1, num);
}
else
return mid;
}

 

How many calls to mystery are made (including the first call) of mystery(0, 4, 5) when arr = {1, 2, 3, 5, 7}?

A) 1

B) 2

C) 3

D) 4

E) 5

Answer 1

Our job is to show you HOW to get an answer. You’re asking us to execute this code by hand. Not muh job.

 

do you have specific questions about this code?

Do you want to know how subscripts Work? Arr[0] = 1, arr[4] =7

Do you want to know whether the “mid” calculation rounds or truncates?

In C, Java and Python, it truncates.

 

If you have other questions, ask them. But only after YOU have desk-executed it first, please.