Time: 3 ms (73.58%), Space: 43 MB (5.53%) - LeetHub

Author: yashcode77

1207-unique-number-of-occurrences/1207-unique-number-of-occurrences.java

@@ -0,0 +1,31 @@
+class Solution {
+    public boolean uniqueOccurrences(int[] arr) {
+
+        HashMap<Integer, Integer> map = new HashMap<>();
+        ArrayList<Integer> list = new ArrayList<>();
+
+        for(int i=0; i<arr.length; i++)
+        {
+            if(map.containsKey(arr[i])) 
+            {
+                map.put(arr[i],map.get(arr[i])+1);
+            }
+            else
+            {
+                map.put(arr[i],1);
+            }
+        }
+        
+        for(Integer i:map.keySet()) 
+        {
+            if(list.contains(map.get(i)))
+            {
+                return false;
+            }
+            list.add(map.get(i));            
+        }
+        return true;
+
+        
+    }
+}