```
class Solution(object):
def removeElement(self, nums, val):
"""
:type nums: List[int]
:type val: int
:rtype: int
"""
i, j, n = 0, 0, len(nums)
while j < n:
if nums[j] != val:
nums[i] = nums[j]
i += 1
j += 1
return i
```