leetcode——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.

不考虑数组排过序

class Solution {
public:
int removeDuplicates(vector<int>& nums) {
if(nums.size() < 3) return nums.size();
int len = 1;
int n = 1;
for(int i = 1; i < nums.size(); i++){
if(nums[i] != nums[i - 1]){
nums[len++] = nums[i];
n = 1;
}
else if(n == 1){
nums[len++] = nums[i];
n++;
}
else
continue;
}
return len;

}
};

考虑数组已排序

class Solution {
public:
int removeDuplicates(vector<int>& nums) {
int n = nums.size();
if(n < 3)
return n;
int index = 2;
for(int i = 2; i < n; i ++)
{
if(nums[i] != nums[index-2])
nums[index ++] = nums[i];
}
return index;

}
};