Maths Assignment - JAVA

// Author : Saurav Kalsoor
// Maths Assignment - JAVA

import java.util.*;

public class Test {

    static Scanner sc = new Scanner(System.in);
    static ArrayList<Long> list = new ArrayList<Long>();
    public static void main(String[] args) {

        long n = sc.nextLong();
        long result = mathsAssignment(n);
        System.out.println(result);

    }

    public static void init(){
        BitSet b = new BitSet(36);
        for(int i=0; i < 36; i++){
            b.set(i);
            for(int j = i+1; j < 36; j++){
                b.set(j);
                long[] longArray = b.toLongArray();
                list.add(longArray[0]);
                b.clear(j);
            }
            b.clear(i);
        }
        Collections.sort(list);
    }

    public static long lessThan(long n){
        int low = 0, high = list.size() - 1, index = 0;
        while(low <= high){
            int mid = low + (high - low) / 2;
            if(list.get(mid) <= n){
                index = mid;
                low = mid + 1;
            }else{
                high = mid-1;
            }
        }
        return list.get(index);
    }

    public static long greaterThan(long n){
        int low = 0, high = list.size() - 1, index = high;
        while(low <= high){
            int mid = low + (high - low) / 2;
            if(list.get(mid) >= n){
                index = mid;
                high = mid - 1;
            }else{
                low = mid + 1;
            }
        }
        return list.get(index);
    }

    public static long mathsAssignment(long n){
        init();
        long a = lessThan(n), b = greaterThan(n);
        long res = Math.min(Math.abs(n - a), Math.abs(n - b));
        return res;
    }

}