leetcode26

public class Solution {
    public int RemoveDuplicates(int[] nums) {
        var len = nums.Length;
            if (len == )
            {
                return ;
            }
            else
            {
                var pre = nums[];
                var diffindex = ;
                for (int i = ; i < nums.Length; i++)
                {
                    if (pre != nums[i])
                    {
                        nums[++diffindex] = nums[i];
                        pre = nums[i];
                    }
                }
                return diffindex + ;
            }
    }
}

python实现如下：

 class Solution:
     def removeDuplicates(self, nums: List[int]) -> int:
         s = set()
         n = len(nums)
         count =
         i,j = ,
         while i < n:
             if len(s) ==  or nums[i] not in s:
                 s.add(nums[i])
                 nums[j] = nums[i]
                 i +=
                 j +=
                 count +=
             else:
                 i +=
         return count

不实用额外的空间，实现如下：

 class Solution:
     def removeDuplicates(self, nums: 'List[int]') -> int:
         n = len(nums)
         i =
         j = i +
         count =
         while i < n:
             while j < n and nums[i] == nums[j]:
                 j +=
             count +=
             if i +  < n and j < n:
                 nums[i+] = nums[j]
                 i +=
             else:
                 return count
         return count