D. J.:

- Added the leetcode problem and solution for 47

Author: nobodyPerfecZ

README.md

@@ -100,6 +100,7 @@
 - [42 Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/description/)
 - [45 Jump Game II](https://leetcode.com/problems/jump-game-ii/description/)
 - [46 Permutations](https://leetcode.com/problems/permutations/description/)
+- [47 Permutations II](https://leetcode.com/problems/permutations-ii/description/)
 - [48 Rotate Image](https://leetcode.com/problems/rotate-image/description/)
 - [49 Group Anagrams](https://leetcode.com/problems/group-anagrams/description/)
 - [50 Pow(x_n)](https://leetcode.com/problems/powx-n/description/)

awesome_python_leetcode/_47_permutations_II.py

@@ -0,0 +1,28 @@
+from typing import List
+
+
+class Solution:
+    """Base class for all LeetCode Problems."""
+
+    def permuteUnique(self, nums: List[int]) -> List[List[int]]:
+        """
+        Given a collection of numbers, nums, that might contain duplicates, return all
+        possible unique permutations in any order.
+        """
+        res = []
+        cache = set()
+
+        def dfs(pair: List[int], rest: List[int]):
+            if tuple(pair) in cache:
+                return
+            if not rest:
+                res.append(pair)
+                cache.add(tuple(pair))
+                return
+            for i, n in enumerate(rest):
+                new_pair = pair + [n]
+                new_rest = rest[:i] + rest[i + 1 :]
+                dfs(new_pair, new_rest)
+
+        dfs([], nums)
+        return res

tests/test_47_permutations_II.py

@@ -0,0 +1,18 @@
+from typing import List
+
+import pytest
+
+from awesome_python_leetcode._47_permutations_II import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["nums", "expected"],
+    argvalues=[
+        ([1, 1, 2], [[1, 1, 2], [1, 2, 1], [2, 1, 1]]),
+        ([1, 2, 3], [[1, 2, 3], [1, 3, 2], [2, 1, 3], [2, 3, 1], [3, 1, 2], [3, 2, 1]]),
+    ],
+)
+def test_func(nums: List[int], expected: List[List[int]]):
+    """Tests the solution of a LeetCode problem."""
+    permutations = Solution().permuteUnique(nums)
+    assert permutations == expected