Merge pull request #2064 from josuebrunel/feat/0047-permutations-ii.py

Create 0047-permutations-ii.py

Author: tahsintunan

Diff for: python/0047-permutations-ii.py

@@ -0,0 +1,25 @@
+import collections
+
+
+class Solution:
+
+    def permuteUnique(self, nums: List[int]) -> List[List[int]]:
+        result = []
+        counter = collections.Counter(nums)
+
+        def backtrack(perm, counter):
+            if len(perm) == len(nums):
+                result.append(perm.copy())
+
+            for n in counter:
+                if counter[n] == 0:
+                    continue
+                perm.append(n)
+                counter[n] -= 1
+                backtrack(perm, counter)
+                perm.pop()
+                counter[n] += 1
+
+        backtrack([], counter)
+
+        return result