leetcode.com 46. Permutations

문제 링크: https://leetcode.com/problems/permutations

Author: skysign

46. Permutations v3/main.py

@@ -0,0 +1,22 @@
+from typing import List
+
+
+class Solution:
+    def permute(self, nums: List[int]) -> List[List[int]]:
+        answer = []
+        visited = [False for _ in range(len(nums))]
+        self.permutation(0, nums, visited, [], 0, answer)
+        return answer
+
+    def permutation(self, bgn, nums, visited, building: List, depth, answer):
+        if depth == len(nums):
+            answer.append(building)
+            return
+
+        for idx in range(len(nums)):
+            if visited[idx]:
+                continue
+
+            visited[idx] = True
+            self.permutation(0, nums, visited, building + [nums[idx]], depth + 1, answer)
+            visited[idx] = False

46. Permutations v3/test_main.py

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+from unittest import TestCase
+from main import Solution
+
+class TestSolution(TestCase):
+    def test1_permute(self):
+        sln = Solution()
+        self.assertEqual(
+            [[1, 2, 3], [1, 3, 2], [2, 1, 3], [2, 3, 1], [3, 1, 2], [3, 2, 1]],
+            sln.permute(nums = [1,2,3])
+        )