update 027.移除元素 python代码

problems/0027.移除元素.md

@@ -199,21 +199,15 @@ Python：
 ```python3
 class Solution:
     def removeElement(self, nums: List[int], val: int) -> int:
-        if nums is None or len(nums)==0: 
-            return 0 
-        l=0
-        r=len(nums)-1
-        while l<r: 
-            while(l<r and nums[l]!=val):
-                l+=1
-            while(l<r and nums[r]==val):
-                r-=1
-            nums[l], nums[r]=nums[r], nums[l]
-        print(nums)
-        if nums[l]==val: 
-            return l 
-        else: 
-            return l+1
+        # 快指针遍历元素
+        fast = 0
+        # 慢指针记录位置
+        slow = 0
+        for fast in range(len(nums)):
+            if nums[fast] != val:
+                nums[slow] = nums[fast]
+                slow += 1
+        return slow
 ```