27_Remove Element

class Solution:
    def removeElement(self, nums, val):
        """
        :type nums: List[int]
        :type val: int
        :rtype: int
        """
        start, end = 0, len(nums) - 1
        while start <= end:
            if nums[start] == val:
                nums[start], nums[end], end = nums[end], nums[start], end - 1
            else:
                start +=1
        return start

s = Solution()
print(s.removeElement([3, 3, 2, 2, 2], 3))