# Remove Duplicates from Sorted Array II

## Question

Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?

For example,
Given sorted array A = [1,1,1,2,2,3],

Your function should return length = 5, and A is now [1,1,2,2,3].
Example


## 题解

### C++

class Solution {
public:
/**
* @param A: a list of integers
* @return : return an integer
*/
int removeDuplicates(vector<int> &nums) {
if (nums.size() <= 2) return nums.size();

int len = nums.size();
int newIndex = 1;
for (int i = 2; i < len; ++i) {
if (nums[i] != nums[newIndex] || nums[i] != nums[newIndex - 1]) {
++newIndex;
nums[newIndex] = nums[i];
}
}

return newIndex + 1;
}
};


### Java

public class Solution {
/**
* @param A: a array of integers
* @return : return an integer
*/
public int removeDuplicates(int[] nums) {
if (nums == null) return -1;
if (nums.length <= 2) return nums.length;

int newIndex = 1;
for (int i = 2; i < nums.length; i++) {
if (nums[i] != nums[newIndex] || nums[i] != nums[newIndex - 1]) {
newIndex++;
nums[newIndex] = nums[i];
}
}

return newIndex + 1;
}
}