LeetCode-Remove Duplicates from Sorted Array II

题目：https://oj.leetcode.com/problems/remove-duplicates-from-sorted-array-ii/

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]

.
源码：Java版本

算法分析：时间复杂度O(n)，空间复杂度O(1)。

public class Solution {
    public int removeDuplicates(int[] A) {
       if(A.length<=2) {
           return A.length;
       }
       int index=2;
       for(int i=2;i<A.length;i++) {
           if(A[i]!=A[index-2]) {
               A[index++]=A[i];
           }
       }
       return index;
    }
}