Leetcode 27 Remove Element

Given an array and a value, remove all instances of that value in place and return the new length.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

双指针基本操作,每个符合要求的都放在前面

class Solution:

    def removeElement(self, nums, val):

        i, j= 0, 0

        while i < len(nums):

            if nums[i] != val:

                nums[j] = nums[i]

                j += 1

            i += 1

        return j

也可以

class Solution:

    def removeElement(self, nums, val):

        nums = [x for x in nums if x != val] 

        return len(nums)

 但是这个方法AC不了。不知道是不是leet的问题