sort

import java.util.*;

public class Solution {
	public int[] solution(int[] nums){
		int[] answer = new int[nums.length];
		int[][] res = new int[nums.length][2];
		
	    //1. 10진수를 2진수로 변환한 값 저장
	    for(int i=0; i<nums.length; i++){
	        int cnt = 0;
	        int tmp = nums[i];
	        while(tmp>0){
	            cnt += (tmp%2);
	            tmp /=2;
	        }
	        res[i][0] = nums[i];
	        res[i][1] = cnt;
	    }
		
		//2. 정렬
		Arrays.sort(res, (a,b) -> a[1] == b[1] ? a[0] - b[0]: a[1]-b[1]);
		
		//3. 정렬된 순서대로 0값만 저장
		for(int i=0 ;i<res.length ; i++){
		    answer[i] = res[i][0];
		}
		
		return answer;
	}

	public static void main(String[] args){
		Solution T = new Solution();
		System.out.println(Arrays.toString(T.solution(new int[]{5, 6, 7, 8, 9})));
		System.out.println(Arrays.toString(T.solution(new int[]{5, 4, 3, 2, 1})));
		System.out.println(Arrays.toString(T.solution(new int[]{12, 5, 7, 23, 45, 21, 17})));
	}
}