80. Remove Duplicates from Sorted Array II

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.

Analysis:

II和I没有太大区别，加个计数变量即可。

Source Code（C++）:

#include <iostream>
#include <vector>
#include <map>
using namespace std;

class Solution {
public:
int removeDuplicates(vector<int>& nums) {
if (nums.empty()) {
return 0;
}
if (nums.size() == 1){
return 1;
}
int index=0;
int count=1;
for (int i=1; i<nums.size(); i++){
if (nums.at(i)!=nums.at(index)){
index++;
nums.at(index)=nums.at(i);
count=1;
}
else if (nums.at(i)==nums.at(index) && count<2)
{
count++;
index++;
nums.at(index)=nums.at(i);
}
}
return index+1;
}
};

int main() {
vector<int> v;
v.push_back(1);v.push_back(1);v.push_back(1);v.push_back(2);v.push_back(2);v.push_back(3);
Solution sol;
cout << sol.removeDuplicates(v) << endl;
return 0;
}