import java.util.Arrays;

public class BinarySearch {
    public static void main(String[] args)
    {
        int[] ary = new int[]{1,4,2,8,4,3,1};
        Arrays.sort(ary);
        int targetElmt = 4;
        int i = binarySearch(ary, 0, ary.length - 1, targetElmt);
        System.out.println("");
    }

    static int binarySearch(int[] ary, int lowerIndex, int higherIndex, int value) {
        if (lowerIndex > higherIndex) {
            // The starting position comes after the final index,
            // so there are actually no elements in the specified
            // range.  The value does not occur in this empty list!
            return -1;
        } else {
            // Look at the middle position in the list.  If the
            // value occurs at that position, return that position.
            // Otherwise, search recursively in either the first
            // half or the second half of the list.
            int middle = (lowerIndex + higherIndex) / 2;
            if (value == ary[middle])
                return middle;
            else if (value < ary[middle])
                return binarySearch(ary, lowerIndex, middle - 1, value);
            else   // value must be > A[middle]
                return binarySearch(ary, middle + 1, higherIndex, value);
        } // end binarySearch()
    }
}