@Test
public void binarySearch() {

    int n = 50;
    int[] array = new int[n];
    for (int i = 0; i < array.length; i++) {
        if (i < 40) {
            array[i] = i;
        } else {
            array[i] = 40;
        }
    }
    int data = 40;
    logger.info("binarySearch, data is: {}, index is: {}", data, DataUtil.binarySearch(array, data));
    logger.info("findFirstEqual, data is: {}, index is: {}", data, DataUtil.findFirstEqual(array, data));
    logger.info("findLastEqualSmaller, data is: {}, index is: {}", data, DataUtil.findLastEqualSmaller(array, data));
}