diff --git "a/14_\345\210\267\351\242\230/problem_solving_02.py" "b/14_\345\210\267\351\242\230/problem_solving_02.py"
index 3fec830920136d27a04bbe2a849fe00a9c22799e..e912ab0ebf39c66d1cb80b9270efb3d438c143f7 100644
--- "a/14_\345\210\267\351\242\230/problem_solving_02.py"
+++ "b/14_\345\210\267\351\242\230/problem_solving_02.py"
@@ -46,13 +46,14 @@ from typing import List
 
 class Solution:
     def removeDuplicates(self, nums: List[int]) -> int:
-        """
-        列表去重后列表的长度
-        :param nums:
-        :return:
-        """
-        result = set(nums)
-        return len(result)
+        if not nums:
+            return 0
+        k = 1
+        for i in range(1, len(nums)):
+            if nums[i] != nums[i - 1]:
+                nums[k] = nums[i]
+                k += 1
+        return k
 
 
 if __name__ == '__main__':