leetcode 题解：Remove Duplicates from Sorted Array II（已排序数组去三次及以上重复元素）

题目：

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].

说明：

     1）设个标志可实现

实现：

class Solution {
public:
    int removeDuplicates(int A[], int n) {
        if(0==n)  return 0;
        int B[n],k=0,flag=1;
        for(int i=0;i<n;i++) 
            B[i]=0;
        B[0]=A[0];
        for(int i=1;i<n;i++)
        {
            if(B[k]==A[i])
               flag++;
            else
               flag=1;
            if(flag<3)
              B[++k]=A[i];
        }
        for(int i=0;i<=k;i++)
            A[i]=B[i];
        return k+1;
    }
};