lintcode-删除排序数组中的重复数字II-101

class Solution {
public:

int removeDuplicates(vector<int> &nums) {
if(nums.empty())
return 0;

map<int,int> check;
int fast=0,slow=0;
while(fast<nums.size()){
if(check[nums[fast]]!=2){
++check[nums[fast]];
if(slow!=fast)
nums[slow]=nums[fast];
++slow;
}
++fast;
}

while(slow++<fast)
nums.pop_back();

return nums.size();
}
};