public static void main(String[] args) {
        int data[] = {9, 15, 32, 71, 78, 92, 101, 115, 117, 129, 270, 350, 470, 500};
        int pos = binarySearch(data, 128);
        System.out.println("position 128 at : " + pos);
        pos = binarySearch(data, 117);
        System.out.print("found 117 at : " + pos);
    }

    private static int binarySearch(int[] data, int key) {
        int position = -1;
        int left = 0;
        int right = data.length - 1;
        int mid = 0;

        while (left <= right) {
            mid = (left + right) / 2;

            if (key > data[mid]) {
                left = mid + 1;

            } else if (key < data[mid]) {
                right = mid - 1;

            } else {
                position = mid;
                break;
            }
        }
        return position; //return index ของ array ที่หาเจอ ถ้าไม่เจอ return -1
    }

    private static int binarySearch(Comparable[] data, Comparable key) {
        int position = 0;

        return position; //return index ของ array ที่หาเจอ ถ้าไม่เจอ return -1
    }