Given a sorted array, 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.
Example:
Given nums = [1,1,2],
Your function should return length = 2,
with the first two elements of nums being 1 and 2 respectively.
It doesn't matter what you leave beyond the new length.
注意点：
- nums 是已经排序好的列表
- 空间复杂度要求为O(1)
解题思路：
因为是排序好的列表，故按次序两两比较，如果相同，则删除。删除后，nums 的长度也会改变，注意下标不要越界。
Python实现：
class Solution:
def removeDuplicates(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
i = 0
while i < len(nums) - 1:
if nums[i] == nums[i+1]: # 两个相邻的元素如果相同
del nums[i]
else:
i += 1
return len(nums)
a = [1,1,2]
b = Solution()
print(b.removeDuplicates(a)) # 2
