python: add problem 46 and unittest

Author: supercoderhawk

Python/solution_41_50.py

@@ -1,8 +1,38 @@
 # -*- coding: UTF-8 -*-
 
 class Solution_41_50:
+    def permute(self, nums):
+        """
+        problem 46
+        Given a collection of distinct numbers, return all possible permutations.
+
+        For example,
+        [1,2,3] have the following permutations:
+        [
+          [1,2,3],
+          [1,3,2],
+          [2,1,3],
+          [2,3,1],
+          [3,1,2],
+          [3,2,1]
+        ]
+
+        :type nums: List[int]
+        :rtype: List[List[int]]
+        """
+        res = [[nums[0]]]
+        for n in nums[1:]:
+            old_res = res
+            res = []
+            print(old_res)
+            for l in old_res:
+                res.extend(list(map(lambda i: l[:i] + [n] + l[i:], range(len(l) + 1))))
+        return res
+
     def groupAnagrams(self, strs):
         """
+        problem 49
+
         Given an array of strings, group anagrams together.
 
         For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"],

Python/test_solution_41_50.py

@@ -1,13 +1,19 @@
 from unittest import TestCase
 from solution_41_50 import Solution_41_50
 
+
 # -*- coding: UTF-8 -*-
 class TestSolution_41_50(TestCase):
-  def setUp(self):
-    self.sln = Solution_41_50()
-
-  def test_groupAnagrams(self):
-    a = ["eat", "tea", "tan", "ate", "nat", "bat"]
-    b = [['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']]
-    self.assertEqual(self.sln.groupAnagrams(a),b)
-    self.assertEqual(self.sln.groupAnagrams(['']), [['']])
+    def setUp(self):
+        self.sln = Solution_41_50()
+
+    def test_permute(self):
+        a = [1, 2, 3]
+        b = [[1, 2, 3], [1, 3, 2], [2, 1, 3], [2, 3, 1], [3, 1, 2], [3, 2, 1]]
+        self.assertCountEqual(self.sln.permute(a), b)
+
+    def test_groupAnagrams(self):
+        a = ["eat", "tea", "tan", "ate", "nat", "bat"]
+        b = [['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']]
+        self.assertCountEqual(self.sln.groupAnagrams(a), b)
+        self.assertCountEqual(self.sln.groupAnagrams(['']), [['']])