Update 1356.根据数字二进制下1的数目排序.md

增加Java实现

problems/1356.根据数字二进制下1的数目排序.md

@@ -123,6 +123,32 @@ public:
 ## Java
 
 ```java
+class Solution {
+    private int cntInt(int val){
+        int count = 0;
+        while(val > 0) {
+            val = val & (val - 1);
+            count ++;
+        }
+
+        return count;
+    }
+
+    public int[] sortByBits(int[] arr) {
+      return Arrays.stream(arr).boxed()
+            .sorted(new Comparator<Integer>(){
+                @Override
+                public int compare(Integer o1, Integer o2) {
+                    // TODO Auto-generated method stub
+                    int cnt1 = cntInt(o1);
+                    int cnt2 = cntInt(o2);
+                    return (cnt1 == cnt2) ? Integer.compare(o1, o2) : Integer.compare(cnt1, cnt2);
+                }
+            })
+            .mapToInt(Integer::intValue)
+            .toArray();
+    }
+}
 ```