public static void main(String args[]){
        int input[] = {1,2,5,6,11,15};
        FloorAndCeilingSortedArray foc = new FloorAndCeilingSortedArray();
        System.out.println(foc.floor(input, 15));
        System.out.println(foc.ceiling(input, 2));
    }
http://www.geeksforgeeks.org/search-floor-and-ceil-in-a-sorted-array/
src/com/interview/binarysearch/FloorAndCeilingSortedArray.java