题目内容
本题来源LeetCode
Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?
For example,
Given sorted array nums = [1,1,1,2,2,3]
,
Your function should return length = 5
, with the first five elements of nums being 1
, 1
, 2
, 2
and 3
. It doesn't matter what you leave beyond the new length.
题目思路
本题难度:medium
这个题目的思路就是经典的快慢指针方法。假如nums的长度小于等于2,则直接返回nums数组。然后设立两个指针i,index。初始化都指向第3个元素,快指针为i,慢指针为index。假如nums[i]!=nums[index-2],则慢指针加一。
Python代码
class Solution(object):
def removeDuplicates(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
l=len(nums)
if l<=2:
return l
index=2
for i in range(2,l):
if nums[i]!=nums[index-2]:
nums[index]=nums[i]
index+=1
return index