Set numbers

 You are given the binary representation of a number. You must consider the highest number of set bits in the binary representation to complete your task. For example, 

$23$ is represented as $10111$ in binary and it contains four set bits (1-bits). You are also given a number $N$ and your task is to determine the number that is less than or equal to $N$ and contains the maximum number of set bits in its binary representation. 

In other words, print a number $K$ that is less than or equal to $N$ such that the number of set bits in the binary representation of $K$ must

Example:

Input:  num=345
Output: 255

Approach

Java

package com.java;
public class SetNumbers {
    public static void main(String[] args) {
        int num = 345;
        int value = 0, j = 0;
        int sum = 0;
        while (true) {
            if (sum > num) {
                sum -= value;
                break;
            }
            value = (int) Math.pow(2, j);
            sum += value;
            j++;
        }

        System.out.println(sum);
    }
}