[Leetcode][python]Remove Element/移除元素

class Solution(object):
    def removeElement(self, nums, val):
        """
        :type nums: List[int]
        :type val: int
        :rtype: int
        """
        front = len(nums)-1
        behind = len(nums)-1
        number = 0
        while front >= 0:
            print 'now:', front, behind
            if nums[front] == val:
                print front, behind
                number += 1
                nums[front], nums[behind] = nums[behind], nums[front]
                behind -= 1
            front -= 1
        print number
        return len(nums) - number

class Solution(object):
    def removeElement(self, nums, val):
        """
        :type nums: List[int]
        :type val: int
        :rtype: int
        """

        size = 0
        length = len(nums)

        for i in range(length):
            if nums[i] != val:

                nums[size] = nums[i]
                size += 1
        return size