leetcode之Remove Duplicates from Sorted Array II

题目：

Follow up for "Remove Duplicates":

What if duplicates are allowed at most twice?

For example,

Given sorted array nums = 

[1,1,1,2,2,3]

,

Your function should return length = 

5

, with the first five elements of nums being 

1

, 

1

, 

2

, 

2

 and 

3

.
It doesn't matter what you leave beyond the new length.

解答：

很明显的用两个指针和计数来做，用一个指针表示现在正在进行计数的数字，另一个指针表示现在处理的位置

代码很明显如下class Solution {
public:
int removeDuplicates(vector<int>& nums) {
int start = 0;
int end = 1;
int size = nums.size();
if(size <= 2)
return size;
int cnt = 1;
while(end < size)
{
if(nums[start] == nums[end])
{
if(cnt < 2)
{
nums[++start] = nums[end++];
}
else
{
end++;
}
cnt++;
}
else
{
nums[++start] = nums[end++];
cnt = 1;
}
}
return start + 1;
}
};