_1356.java

packagecom.fishercoder.solutions.secondthousand;

importjava.util.ArrayList;
importjava.util.Collections;
importjava.util.HashMap;
importjava.util.List;
importjava.util.Map;

publicclass_1356 {
publicstaticclassSolution1 {
publicint[] sortByBits(int[] arr) {
Map<Integer, List<Integer>> map = newHashMap<>();
for (intnum : arr) {
intcount = Integer.bitCount(num);
if (!map.containsKey(count)) {
map.put(count, newArrayList<>());
 }
map.get(count).add(num);
 }
int[] result = newint[arr.length];
inti = 0;
for (intcount : map.keySet()) {
List<Integer> list = map.get(count);
Collections.sort(list);
for (intnum : list) {
result[i++] = num;
 }
 }
returnresult;
 }
 }
}