[update]个人最优解

Author: Dream

algorithms/uniqueNumberOfOccurrences/uniqueNumberOfOccurrences.java

@@ -0,0 +1,18 @@
+
+class Solution {
+    public boolean uniqueOccurrences(int[] arr) {
+        Map<Integer, Integer> map = new HashMap(arr.length);
+        for(int i : arr){
+            map.put(i, map.getOrDefault(i, 0) + 1);
+        }
+        Map<Integer, Integer> map2 = new HashMap<>(map.size());
+        for (Map.Entry<Integer, Integer> entry : map.entrySet()) {
+            Integer value = entry.getValue();
+            map2.put(value, map2.getOrDefault(value, 0) + 1);
+            if (map2.get(value) > 1) {
+                return false;
+            }
+        }
+        return true;
+    }
+}