Create unique-number-of-occurrences.py

Author: kamyu104

Python/unique-number-of-occurrences.py

@@ -0,0 +1,31 @@
+# Time:  O(n)
+# Space: O(n)
+
+import collections
+
+
+class Solution(object):
+    def uniqueOccurrences(self, arr):
+        """
+        :type arr: List[int]
+        :rtype: bool
+        """
+        count = collections.Counter(arr)
+        lookup = set()
+        for v in count.itervalues():
+            if v in lookup:
+                return False
+            lookup.add(v)
+        return True
+
+
+# Time:  O(n)
+# Space: O(n)
+class Solution2(object):
+    def uniqueOccurrences(self, arr):
+        """
+        :type arr: List[int]
+        :rtype: bool
+        """
+        count = collections.Counter(arr)
+        return len(count) == len(set(count.itervalues()))