NO27.移除元素

#还是双指针，与上一道题相似
class Solution:
    def removeElement(self, nums: List[int], val: int) -> int:
        fast,slow = 0,0
        while fast<len(nums):
            if nums[fast]!=val:
                nums[slow]=nums[fast]
                slow+=1
            fast+=1
        return slow