Remove Duplicates from Sorted Array II

问题：

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].

思路：

　　双指针--遍历指针和当前应该写的位置指针

　　和Remove Duplicates from Sorted Array类似，仅仅多了一个频次而已。

我的代码：

public class Solution {
    public int removeDuplicates(int[] A) {
        if(A == null || A.length == 0)  return 0;
        int cur = 1;
        int count = 1;
        for(int i = 1; i < A.length; i++)
        {
            if(A[i] == A[i-1])
            {
                count++;
                if(count < 3)
                {
                    A[cur++] = A[i];
                }
            }
            else
            {
                A[cur++] = A[i];
                count = 1;
            }
        }
        return cur;
    }
}

View Code

学习之处：

A[cur++] = num 等价于A[cur] = num ; cur++