Answer:
10
-1
Process finished with exit code 0
Explanation: see code bellow
public class BinarySearchRecursive {
public static int binarySearch(int[] a, int key) {
return binarySearchRecursiveHelper(a, key, 0, a.length - 1);
}
public static int binarySearchRecursiveHelper(int[] arr, int target, int start, int end) {
if (start > end) {
return -1;
}
int mid = (start + end) / 2;
if (arr[mid] == target) {
return mid;
} else if (target < arr[mid]) {
return binarySearchRecursiveHelper(arr, target, start, mid - 1);
} else {
return binarySearchRecursiveHelper(arr, target, mid + 1, end);
}
}
public static void main(String[] args) {
int[] a = {-4, 2, 7, 10, 15, 20, 22, 25, 30, 36, 42, 50, 56, 68, 85, 92, 103};
int index = binarySearch(a, 42); // 10
System.out.println(index);
index = binarySearch(a, 66); // -1
System.out.println(index);
}
}
