diff --git a/notes/面试总结.md b/notes/面试总结.md
index 68dfab57..867fb55c 100644
--- a/notes/面试总结.md
+++ b/notes/面试总结.md
@@ -211,9 +211,8 @@ def duplicate(nums):
         while nums[i] != i:
             if nums[i] == nums[nums[i]]:
                 return nums[i], True
-            t = nums[i]
-            nums[i]  = nums[nums[i]]
-            nums[nums[i]] = t
+            index = nums[i]
+            nums[i], nums[index] = nums[index], nums[i]
             # nums[i], nums[nums[i]] = nums[nums[i]], nums[i]
     return -1, False