27. Remove Element

题目链接

 

 思路一：直接遍历删除并记录个数就可以

class Solution:
    def removeElement(self, nums,val):
        sum = 0
        for i in range(len(nums)):
            if nums[i] != val:
                nums[sum] = nums[i]
                sum += 1
        nums = nums[:sum]
        return  sum

思路二:利用count函数和remove函数

class Solution:
    def removeElement(self, nums: List[int], val: int) -> int:
        a = nums.count(val)
        for i in range(a):
            nums.remove(val)
        return len(nums)