python: add problem 80 and unittest

Author: supercoderhawk

Python/sln_1_100/solution_81_90.py

@@ -4,6 +4,28 @@
 
 
 class Solution_81_90(object):
+    def removeDuplicates(self, nums: List[int]) -> int:
+        """
+        80
+        :param nums:
+        :return:
+        """
+
+        if len(nums) <= 2:
+            return 2
+        indicator = nums[0] ^ nums[1]
+        idx = 1
+        actual_len = len(nums)
+        while idx < actual_len - 1:
+            new_indicator = nums[idx] ^ nums[idx + 1]
+            if indicator == 0 and new_indicator == 0:
+                nums[idx:] = nums[idx + 1:]
+                actual_len -= 1
+                idx -= 1
+            idx += 1
+            indicator = new_indicator
+        return actual_len
+
     def partition(self, head: ListNode, x: int) -> ListNode:
         """
         86

Python/sln_1_100/test_solution_81_90.py

@@ -8,6 +8,12 @@ class Test_Solution_81_90(TestCase):
     def setUp(self) -> None:
         self.sln = Solution_81_90()
 
+    def test_removeDuplicates(self):
+        arr = [1, 1, 1, 2, 2, 3]
+        self.assertEqual(self.sln.removeDuplicates(arr), 5)
+        arr1 = [1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 5]
+        self.assertEqual(self.sln.removeDuplicates(arr1), 9)
+
     def test_partition(self):
         head = build_linked_list([1, 4, 3, 2, 5, 2])
         ret = self.sln.partition(head, 3)