1356. Sort Integers by The Number of 1 Bits.java

public class Solution {
    public int[] sortByBits(int[] arr) {
       for(int i=0;i<arr.length;i++){
            arr[i]+=Integer.bitCount(arr[i])*10001; 
        }
        
        Arrays.sort(arr);
        
        for(int i=0;i<arr.length;i++){  
            arr[i]=arr[i]%10001;
        }
        
        return arr;

    }
}