Binary search method for an array in java.

Problem:

Writing a binary search method for an array in java.

Output:

Not applicable.

Solution:

// Returns the index of an occurrence of the given value in
// the given array, or a negative number if not found.
// Precondition: elements of a are in sorted order
public static int binarySearch(int[] a, int target) {
return binarySearch(a, target, 0, a.length - 1);
}
// Recursive helper to implement search behavior.
private static int binarySearch(int[] a, int target,
int min, int max) {
if (min > max) {
return -1; // target not found
} else {
int mid = (min + max) / 2;
if (a[mid] < target) { // too small; go right
return binarySearch(a, target, mid + 1, max);
} else if (a[mid] > target) { // too large; go left
return binarySearch(a, target, min, mid - 1);
} else {
return mid; // target found; a[mid] == target
}
}
}