Qustion
Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length.
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
增加一个count来计数，从左至右遍历，遇到相同的直接
del，否则count += 1
class Solution:
def removeDuplicates(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
count = 0
while count < len(nums)-1:
if nums[count]==nums[count+1]:
# The same with nums.pop(count) or nums.remove(nums[count])
del nums[count]
else:
count += 1
return len(nums)
